UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

FOR THE MONTH OF DECEMBER 2018

COMMISSION FILE NUMBER 333-04906

SK Telecom Co., Ltd.

(Translation of registrant’s name into English)

Euljiro65(Euljiro2-ga), Jung-gu

Seoul 100-999, Korea

(Address of principal executive offices)

(Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.)

Form 20-F  ☒             Form 40-F  ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Note: Regulation S-T Rule 101(b)(1) only permits the submission in paper of a Form 6-K if submitted solely to provide an attached annual report to security holders.

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):  ☐

Note: Regulation S-T Rule 101(b)(7) only permits the submission in paper of a Form 6-K if submission to furnish a report or other document that the registration foreign private issuer must furnish and make public under the laws of the jurisdiction in which the registrant is incorporated, domiciled or legally organized (the registrant’s “home country”), or under the rules of the home country exchange on which the registrant’s securities are traded, as long as the report or other document is not a press release, is not required to be and has not been distributed to the registrant’s security holders, and if discussing a material event, has already been the subject of a Form 6-K submission or other Commission filing on EDGAR.

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.    Yes  ☐    No  ☒

If “Yes” is marked, indicate below the file number assigned to the Registrant in connection with Rule 12g3-2(b): 82-

QUARTERLY BUSINESS REPORT

(From January 1, 2018 to September 30, 2018)

THIS IS A SUMMARY OF THE QUARTERLY BUSINESS REPORT ORIGINALLY PREPARED IN KOREAN WHICH IS IN SUCH FORM AS REQUIRED BY THE KOREAN FINANCIAL SERVICES COMMISSION.

IN THE TRANSLATION PROCESS, SOME PARTS OF THE REPORT WERE REFORMATTED, REARRANGED OR SUMMARIZED FOR THE CONVENIENCE OF READERS.

ALL REFERENCES TO THE “COMPANY” SHALL MEAN SK TELECOM CO., LTD. AND, UNLESS THE CONTEXT OTHERWISE REQUIRES, ITS CONSOLIDATED SUBSIDIARIES. REFERENCES TO “SK TELECOM” SHALL MEAN SK TELECOM CO., LTD., BUT SHALL NOT INCLUDE ITS CONSOLIDATED SUBSIDIARIES.

UNLESS EXPRESSLY STATED OTHERWISE, ALL INFORMATION CONTAINED HEREIN IS PRESENTED ON A CONSOLIDATED BASIS IN ACCORDANCE WITH THE INTERNATIONAL FINANCIAL REPORTING STANDARDS ADOPTED FOR USE IN KOREA (“K-IFRS”) WHICH DIFFER IN CERTAIN RESPECTS FROM GENERALLY ACCEPTED ACCOUNTING PRINCIPLES IN CERTAIN OTHER COUNTRIES, INCLUDING THE UNITED STATES. WE HAVE MADE NO ATTEMPT TO IDENTIFY OR QUANTIFY THE IMPACT OF THESE DIFFERENCES.

The Company’s quarterly business report for the nine months ended September 30, 2018 includes the following consolidated subsidiaries:

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Changes in subsidiaries during the nine months ended September 30, 2018 are set forth below.

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The Company provides wireless telecommunications services, characterized by its competitive strengths in handheld devices, affordable pricing, network coverage and an extensive contents library. The Company continues to maintain its reputation as the unparalleled premium network operator in the 2G, 3G and LTE markets on the basis of its technological leadership and network management technology. In addition, the Company is leading the process of global technology standardization with the aim of being the world’s first to commercialize 5G technology.

In order to strengthen its sales channels, the Company has been offering a variety of fixed-line and wireless telecommunication convergence products through its subsidiary, PS&Marketing Co., Ltd. (“PS&Marketing”). PS&Marketing provides differentiated service to customers through the establishment of new sales channels and product development. Through its subsidiaries Service Ace Co., Ltd. and Service Top Co., Ltd., the Company operates customer service centers in Seoul and provides telemarketing services. Additionally, Network O&S Co., Ltd., the Company’s subsidiary responsible for the operation of the Company’s 2G to 4G networks, provides customers with quality network services and provides the Company with technological know-how in network operations.

The Company plans to increase its profitability by strengthening its retention policy, which is the fundamental basis of competitiveness for telecommunication companies in this data-intensive era. The Company will lead the information and communication technology (“ICT”) trend by providing products through which customers can have a distinctive experience and by providing innovative services to transition to service-based competition.

In addition to the mobile network operator (“MNO”) business, the Company is building next-generation growth businesses in Internet of Things (“IoT”) solutions and artificial intelligence. In July 2016, the Company deployed the world’s first low-cost Low Power Wide Area Network designed to support IoT devices based on LoRa technology. In September 2016, the Company launched NUGU, the first intelligent virtual assistant service launched in Korea with Korean language capabilities based on advanced voice recognition technologies. The Company plans to further utilize its big data analysis capabilities to achieve growth in new business areas such as artificial intelligence.

SK Broadband Co., Ltd. (“SK Broadband”) is engaged in providing telecommunications, broadcasting and new media services and various other services that are permitted to be carried out by SK Broadband under relevant regulations, as well as business activities that are directly or indirectly related to providing those services. In 1999, SK Broadband launched its high-speed Internet service in Seoul, Busan, Incheon and Ulsan and currently provides such services nationwide. SK Broadband also commercialized its TV-Portal service in July 2006 and its IPTV service in January 2009 upon receipt of permit in September 2008.

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The Company is a leading player in the Korean e-commerce industry with 11st, an e-commerce platform service that connects various sellers and purchasers through its online and mobile platforms, and “Shocking Deal,” a mobile commerce curation service. In addition, the Company continues to expand its e-commerce businesses by providing differentiated shopping-related services covering shopping information, product search and purchases, relying on the strength of the Company’s core principles of innovation supported by its advanced technological capabilities, including AI-based commerce search technology and customized recommendations based on big data analysis.

In the online-to-offline (“O2O”) area, the Company is a leading player and continues to expand its market power with OK Cashbag, Korea’s largest loyalty mileage program, SyrupWallet, which offers smart shopping services utilizing its network of business partners and information technology such as big data, and other Syrup-related services such as gifticon and 11Pay. The Company focuses on the mobile platform to connect various on- and offline commerce service platforms that provide various benefits and information at the right place and the right time to give consumers a pleasant and convenient shopping experience and retailers an integrated marketing solution to reach their target audience. The Company intends to continue its efforts to secure the market leading position in these markets.

In the location-based services business area, the Company provides real time traffic information and various local information through its T-Map Navigation service. In the digital contents business area, the Company provides high-quality digital contents in its leading mobile contents marketplace, Onestore.

The Company is also engaged in display advertising and search engine-based advertising and provides contents and other services. Display advertising provides exposure to the advertiser’s brand in the form of flash media, images or videos. Search engine-based advertising provides exposure through the search results of specific keywords entered in the NATE search engine, and is utilized mostly by small and medium-sized advertisers. The Company also derives revenue by providing contents and other services.

See “II-1. Business Overview” for more information.

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June 2015: Consummation of the comprehensive share exchange transaction (the “Share Exchange”) through which the Company acquired all of the shares of SK Broadband that it did not otherwise own in exchange for its treasury shares such that SK Broadband became a wholly-owned subsidiary of the Company.

April 2016: The spin-off and merger of the location-based services business and the mobile phone verification services business of SK Planet Co., Ltd.

December 2017: Comprehensive exchange of shares of SK Telink following which SK Telink became a wholly-owned subsidiary of the Company.

At the 30th General Meeting of Shareholders held on March 21, 2014, Jae Hoon Lee was elected as an independent director and Jae Hyeon Ahn was elected as an independent director and member of the audit committee of the Company’s board of directors. At the 31st General Meeting of Shareholders held on March 20, 2015, Dong Hyun Jang was elected as an inside director. At the 32nd General Meeting of Shareholders held on March 18, 2016, Dae Sik Cho was re-elected as an inside director and Dae Shick Oh was re-elected as an independent director and member of the audit committee of the Company’s board of directors. At the 33rd General Meeting of Shareholders held on March 24, 2017, Jung Ho Park was elected as an inside director and Dae Sik Cho was elected as a non-executive director. Jae Hoon Lee and Jae Hyeon Ahn were re-elected as independent directors and members of the audit committee and Jung Ho Ahn was elected as an independent director. At the 34th General Meeting of Shareholders held on March 21, 2018, Young Sang Ryu was elected as an inside director and Youngmin Yoon was elected as an independent director and member of the audit committee of the Company’s board of directors.

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On January 2, 2017, SK M&Service Co., Ltd., one of the Company’s subsidiaries, changed its name to SK M&Service Co., Ltd. from M&Service Co., Ltd. in accordance with a resolution at its general meeting of shareholders on December 26, 2016.

On March 23, 2017, Neosnetworks Co., Ltd., one of the Company’s subsidiaries, changed its name to NSOK Co., Ltd., from Neosnetworks Co., Ltd., in accordance with a resolution at its general meeting of shareholders.

On February 20, 2014, the board of directors of the Company resolved to invest an additional Won 100 billion (20 million common shares) into PS&Marketing, an affiliated company, in order to increase its mid- to long-term competitiveness in distribution. The date of investment was April 2, 2014, and the cumulative investment amount totaled Won 330 billion.

On March 10, 2014, the Company disposed of 3,790,000 shares (its 9.4% equity share) of iHQ Inc. to rebalance its investment portfolio.

In order to acquire a new growth engine, the Company acquired a controlling stake in NSOK, a building security company, with the purchase of 31,310 shares (a 66.7% equity interest) of NSOK on April 2, 2014. The Company acquired an additional 50,377 shares in NSOK in April 2015 through a rights offering, resulting in an increase of its ownership to 83.9%.

On August 13, 2014, the Company purchased 10,241,722 shares (a 39.3% equity interest) of Iriver Ltd. (“Iriver”) from Vogo-Rio Investment Holdings Co., Ltd. and KGF-Rio Limited in order to foster application development and smartphone accessories as part of the Company’s growth engines. The Company holds a 48.9% equity interest of Iriver by acquiring additional shares in its rights offering. The Company does not hold a majority of the voting rights of Iriver but the Company has concluded that it has effective control, as it holds significantly more voting rights than any other shareholder or any organized group of shareholders.

On October 10 2014, SK Planet America LLC, a subsidiary of the Company, acquired (through its 95.2%-owned subsidiary Shopkick Management Company, Inc.) a 100.0% ownership interest in Shopkick, a developer of a shopping app for mobile devices that provides benefits to customers for visiting stores, in order to penetrate the mobile commerce market in the United States. In the first half of 2016, SK Planet America LLC acquired all remaining shares of Shopkick Management Company, Inc.

In 2014, the Company entered into an agreement to dispose of its equity interest in Shenzen E-eye in order to focus its business portfolio on high-growth business areas in the Chinese ICT market. The sale was completed on March 23, 2015.

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On April 3, 2015, the Company sold 27,725,264 shares (10.4% out of the 25.4% equity interest the Company held prior to the sale) of KEB Hana Card Co., Ltd. to Hana Financial Group in cash. With the proceeds of such sale (Won 180 billion), the Company acquired equity interests in Hana Financial Group on April 17, 2015 through participation in a rights offering by Hana Financial Group. The Company plans to maintain its strategic alliance and pursue opportunities to create synergies with, Hana Financial Group.

On March 20, 2015, the Company’s board of directors resolved to approve the Share Exchange.

In July 2015, SK Planet spun off its cloud streaming division and established Entrix Co., Ltd. The Company exchanged 1,300,000 shares of SK Planet for 1,300,000 shares of Entrix at the time of the spin-off and later acquired an additional 2,857,000 shares by participating in the recapitalization.

In 2015, the Company acquired 1,090,155 shares through the additional capital raise by NanoEnTek.

In 2015, the Company reclassified its investments in Packet One from investments in associates and joint ventures to assets classified as held for sale as the Company no longer had significant control over Packet One. The difference between the book value and the fair value of Won 37.4 billion at the time of reclassification was recognized as impairment loss.

On October 1, 2015, the Company became the largest shareholder of SK Communications with a 64.54% equity interest through dividends in kind from SK Planet of 26,523,815 shares and the purchase of 1,506,130 shares over-the-counter.

On November 2, 2015, the Company’s board of directors resolved to approve the acquisition of CJ HelloVision’s shares from CJ O Shopping Co., Ltd. (“CJ O Shopping”) and on the same day, entered into a share purchase agreement with CJ O Shopping. In addition, on November 2, 2015, SK Broadband’s board of directors resolved to approve the merger of SK Broadband with CJ HelloVision and on the same day, entered into a merger agreement with CJ HelloVision and the closing of the merger was conditioned upon receipt of regulatory approval from relevant authorities. On July 25, 2016, the Company notified CJ O Shopping of the termination of the share purchase agreement and SK Broadband notified CJ HelloVision of the termination of the merger agreement, as the Korea Fair Trade Commission on July 18, 2016 denied approval of the proposed merger, which was a closing condition to the consummation of the merger.

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From November 2, 2015 to November 23, 2015, the Company purchased 6,671,933 shares of CJ Hellovision in a tender offer for up to 10,000,000 shares, paying Won 12,000 per share. Through this tender offer, the Company acquired an 8.61% equity interest in CJ HelloVision.

In March 2016, SK Planet spun off its platform business and T Store business and established SK TechX and Onestore. The Company exchanged 12,323,905 shares of SK Planet for 6,323,905 shares of SK TechX and 6,000,000 shares of Onestore at the time of the spin-off. The Company later acquired an additional 4,409,600 shares of Onestore at a purchase price of Won 22 billion by participating in the follow-on rights offering. The Company did not participate in the subsequent follow-on rights offering and as of September 30, 2018, the Company had a 65.5% interest in Onestore.

Through the merger of SK Planet’s location-based services business and mobile phone verification services business into SK Telecom, the Company seeks to provide a solid base for continued growth, especially in the next generation platform business, and SK Planet plans to further concentrate its resources on its commerce business. The spin-off and merger was effective as of April 5, 2016 and was registered as of April 7, 2016. SK Planet is a wholly-owned subsidiary of the Company, and as the Company did not issue any new shares in connection with the merger, there was no change in the share ownership of the Company.

In order to provide an everyday finance platform, the Company entered into a joint venture agreement with Hana Financial Group, in accordance with the resolution of the Company’s board of directors on July 28, 2016. Combining the Company’s leading mobile technology and big data analysis capabilities with Hana Financial Group’s financial service, Hana-SK Fintech Corporation plans to provide innovative mobile financial services such as mobile asset management, easy payment and overseas wire transfer services. SK Telecom holds a 49% equity stake in the joint venture, and Hana Financial Group holds the remaining 51%. Service of the everyday finance platform Finnq officially launched in the third quarter of 2017.

On October 25, 2016, the Company made a capital contribution of all shares of NSOK owned by the Company to SK Telink in exchange for 219,967 newly issued shares of SK Telink, which resulted in an increase of the Company’s equity interest in SK Telink to 85.86%.

In October 2016, the Company transferred the media platform businesses Hotzil and 5Ducks to SM Mobile Communications in exchange for 1,200,000 shares of SM Mobile Communications. As a result, the Company owned a 46.2% equity interest in SM Mobile Communications as of September 30, 2018.

On November 24, 2016, the Company’s board of directors resolved to approve the payment of cash consideration in lieu of the issuance of shares of the Company in a comprehensive exchange of shares of SK Communications. The amount of cash consideration was based on a share exchange ratio of one common share of the Company to 0.0125970 common share of SK Communications. In February 2017, SK Communications became a wholly-owned subsidiary of the Company.

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The Company acquired 4,699,248 shares of its subsidiary Iriver Ltd. at a purchase price of Won 5,320 in connection with a capital contribution. The Company’s equity interest in Iriver Ltd. following the acquisition is 45.9%. See “Report on Important Business Matters (Decision on Capital Increase)” filed on July 17, 2017 by Iriver Ltd. for more information.

On July 28, 2017, the Company acquired newly issued shares of SK China to find investment opportunities in ICT and other promising areas of growth in China. In exchange for newly issued shares of SK China, the Company contributed its full equity interest in each of SKY Property Management Limited (“SKY”) and SK Industrial Development China Co., Ltd. (“SK IDC”) as well as cash, equal to the following amounts: 1) SKY stock: USD 276,443,440.64, 2) SK IDC stock: USD 108,072,007.67 and 3) Cash: USD 100,000,000.00. As a result of the acquisition, the Company holds 10,928,921 shares and a 27.27% of equity interest in SK China. See “Report on Decision on Acquisition of SK China Shares” filed by the Company on July 28, 2017 for more information about this transaction.

On September 28, 2017, the Company disclosed a resolution approving the payment of cash consideration in lieu of the issuance of shares of SK Telecom in an exchange of shares of SK Telink. The amount of cash consideration was based on a share exchange ratio of 1:1.0687714. The exchange was completed on December 14, 2017, upon which exchange SK Telink became a wholly-owned subsidiary of the Company.

On February 6, 2016, the Company acquired 2,415,750 shares of FSK L&S Co., Ltd. at a purchase price of Won 17.8 billion from SK Holdings to utilize its logistics sharing infrastructure with its counterparties and pursue new business opportunities. As a result of the acquisition, the Company had a 60% equity interest in FSK L&S Co., Ltd.

In order to increase the value of the Company by enhancing its position as the top MNO through utilizing quantum cryptography and by generating returns from its global business, the Company acquired an additional 41,157,506 shares of id Quantique SA on April 30, 2018. As a result, the Company owns a total of 58.1% of the issued and outstanding shares (44,157,506 shares), and has acquired control, of id Quantique SA.

The Company decided to acquire shares of Siren Holdings Korea Co., Ltd. (“SHK”), which wholly owns ADT CAPS Co., Ltd. (“ADT CAPS”), in order to strengthen its security business and expand its residential customer base. The number of SHK’s shares to be acquired by the Company refers to the number of shares after the following steps have been taken, which are expected to occur within approximately two months from the date of the purchase agreement, rather than the board approval date: Siren Investments Korea Co., Ltd. will be merged with and into SHK with SHK as the surviving entity, following which CAPSTEC Co., Ltd. and ADT Security Co., Ltd., which are subsidiaries of ADT CAPS, will become subsidiaries of SHK. See “Report on Decision on Acquisition of Shares of Siren Holdings Korea Co., Ltd.” filed on May 8, 2018 for more information.

On July 26, 2018, the board of directors of Iriver Ltd., a subsidiary of the Company, resolved to approve a capital increase of Won 70,000 million through third-party allotment and subsequently issued 7,990,867 common shares. The Company participated in the capital increase and paid Won 65,000 million to subscribe 7,420,091 common shares of Iriver Ltd. on August 10, 2018, resulting in an increase of the Company’s ownership interest from 45.9% to 53.7%.

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[SK Broadband]

On March 20, 2015, the board of directors of SK Broadband resolved to approve the comprehensive exchange of shares of SK Broadband for shares of the Company. The share exchange was approved at the extraordinary meeting of shareholders held on May 6, 2015. Subsequent to the share exchange, the Company became the parent company of SK Broadband with 100% ownership and remained a listed corporation on the KRX KOSPI Market, and SK Broadband became a wholly-owned subsidiary of the Company and was delisted from the KRX KOSDAQ Market. There was no change in the share ownership interest of the Company’s existing shareholders or the Company’s management in connection with the Share Exchange.

On July 29, 2015, the board of directors of SK Broadband approved the acquisition of SK Planet’s Hoppin business through a spin-off and subsequent merger transaction pursuant to Article 530-2 of the Korean Commercial Code, with both SK Broadband and SK Planet remaining as existing companies. The spin-off and subsequent merger were effective as of September 1, 2015, and on the same day, SK Broadband issued 2,501,125 new common shares resulting from the merger, allotting 0.0349186 common shares of SK Broadband per one common share of SK Planet to SK Telecom, SK Planet’s sole shareholder.

On November 2, 2015, SK Broadband’s board of directors resolved to approve the merger of SK Broadband with CJ HelloVision such that CJ HelloVision would be the surviving entity and SK Broadband would be the non-surviving entity. The largest shareholder of the merged entity would be SK Telecom with an equity interest of 78.35%. On February 26, 2016, the entry into the merger agreement was resolved as proposed by SK Broadband’s shareholders.

On July 25, 2016, SK Broadband notified CJ HelloVision of the termination of the merger agreement, as the Korea Fair Trade Commission on July 18, 2016 denied approval of the proposed merger, which was a closing condition to the consummation of the merger. On July 27, 2016, SK Broadband’s board of directors resolved to terminate the merger agreement as proposed. Subsequently, the merger agreement is no longer effective and all procedures related to the merger, including the issuance of new shares, were terminated.

On May 23, 2017, SK Broadband’s board of directors resolved to approve the establishment of a subsidiary. On June 5, 2017, SK Broadband established Home&Service Co., Ltd. (“Home&Service”), a subsidiary responsible for the management of customer service operations, in order to enhance SK Broadband’s competitiveness by strengthening its customer service and strategically developing its home Value Delivery channel and to create quality jobs. Home&Service was incorporated by SK Broadband under the Korean Commercial Code. The subsidiary was capitalized at Won 46 billion (9,200,000 shares with par value of Won 5,000 per share), and SK Broadband holds a 100% equity interest. The Korea Fair Trade Commission approved the subsidiary’s incorporation as an SK affiliate on July 1, 2017, from which arises a duty to report to the Fair Trade Commission.

On August 16, 2017, SK Broadband’s board of directors resolved to approve the spin-off of its T-commerce subsidiary to enhance the competitiveness and managerial efficiency of its T-commerce business (data broadcasting and commercial retail platform service through TV home shopping channels) through a spin-off and subsequent establishment of a subsidiary pursuant to Article 530-2 and 530-12 of the Korean Commercial Code, with both companies from the simple vertical spin-off remaining as existing companies. The spin-off was effective as of December 1, 2017, and the subsidiary was capitalized at Won 15 billion (3,000,000 shares with par value of Won 5,000 per share), with SK Broadband holding a 100% equity interest. The Korea Fair Trade Commission approved the subsidiary’s incorporation as an SK affiliate on January 1, 2018, from which arises a duty to report to the Fair Trade Commission.

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[SK Planet]

On May 29, 2015, the board of directors of SK Planet resolved to spin off its cloud streaming division on July 1, 2015 in order to strengthen its business capabilities and expand overseas. The spin-off ratio was 0.9821740 for the surviving company to 0.0178260 for the newly-established company, and the capital reduction ratio was 1.7825968%.

On July 29, 2015, the board of directors of SK Planet resolved to spin off its Hoppin business, which was merged into SK Broadband on September 1, 2015, in order to unify capabilities within the business and maximize synergies to improve its competitive power in the Korean and international mobile media market. SK Planet issued 2,501,125 new common shares in connection with this transaction, and the merger ratio between SK Planet and SK Broadband was 0.0349186:1.

On December 29, 2015, the board of directors of SK Planet resolved to merge Commerce Planet Co., Ltd., its wholly-owned subsidiary, into SK Planet to generate synergies by uniting capabilities to promote its commerce business. The merger was effective as of February 1, 2016, and SK Planet did not issue any new shares in connection with the merger.

Effective as of March 1, 2016, SK Planet spun off its platform business and T Store business in order to enhance the competitiveness of each business for future growth.

Effective as of April 5, 2016, SK Planet spun off its location-based services business and mobile phone verification services business and merged them into the Company in order to further concentrate its resources on its commerce business.

On May 29, 2017, the board of directors of SK Planet resolved to transfer the operations and assets related to its BENEPIA business for Won 7.5 billion to SK M&Service Co., Ltd. as of July 1, 2017.

On July 17, 2017, the board of directors of SK Planet resolved to (1) spin-off SK Planet’s advertising agency business as a newly established company, SM Contents & Communications, in order to strengthen the competitiveness of the business for future growth, which spin-off was effective as of October 1, 2017 and (2) sell 100% of its shares of SM Contents & Communications to SM Culture & Contents Co., Ltd. to further concentrate business capabilities and efficiently allocate management resources. The closing date of the sale transaction was October 24, 2017.

On June 19, 2018, the board of directors of SK Planet resolved to spin off its 11st business (including Scinic, Gifticon and 11pay) into a newly established company, effective as of September 1, 2018, in order to enhance the level of specialization and competitiveness of its businesses by strengthening their core competencies and obtain further growth potential of the businesses. See the “Report on Decision on Spin-off of SK Planet’s 11st Business” filed on June 19, 2018 for more information.

On June 19, 2018, the board of directors of SK Planet resolved to merge SK TechX Co., Ltd. (“SK TechX”) with and into SK Planet, effective as of September 1, 2018, with a merger ratio between SK Planet and SK TechX of 1:3.0504171, in order to enhance management efficiency and create synergies. See the “Report on Decision on Merger of SK TechX into SK Planet” filed on June 19, 2018 for more information.

[SK Telink]

In accordance with the resolution of its board of directors on September 22, 2016, SK Telink received a capital contribution of 408,435 shares (an 83.9% equity interest) of NSOK owned by SK Telecom. On October 25, 2016, SK Telink acquired the remaining 78,200 outstanding shares (a 16.1% equity interest) of NSOK, pursuant to which NSOK became a wholly-owned subsidiary of SK Telink.

In accordance with the resolution of its board of directors on April 12, 2017, SK Telink acquired 525,824 additional shares of NSOK pursuant to a rights offering for an aggregate amount of Won 40.0 billion (or Won 76,071 per share), resulting in SK Telink’s ownership of 1,012,459 shares (a 100% equity interest) of NSOK.

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On September 28, 2017, SK Telink’s board of directors approved a comprehensive exchange of shares with SK Telecom, pursuant to which SK Telecom would acquire SK Telink’s remaining outstanding shares for cash consideration in lieu of issuance of shares of SK Telecom. The share exchange agreement was subsequently approved at the extraordinary general meeting of shareholders held on November 9, 2017.

Following the exchange, there were no changes to SK Telecom’s share ownership interest level or to management structure, and SK Telecom and SK Telink will remain as corporate entities. SK Telink became a wholly-owned subsidiary of SK Telecom and remains as an unlisted corporation, while SK Telecom remains as a listed corporation.

ø See “Report on Cash Consideration for Shares of SK Telink Co., Ltd.” filed on September 29, 2017 for more information about this transaction.

[SK Communications]

Pursuant to the resolution of its board of directors on March 6, 2014, SK Communications sold its Cyworld service and certain related assets to Cyworld Co., Ltd. for Won 2.8 billion on April 8, 2014.

On September 24, 2015, SK Telecom and SK Planet entered into a share transfer agreement to transfer all of the shares of SK Communications held by SK Planet to SK Telecom. The agreement became effective on October 1, 2015, making SK Telecom the largest shareholder of SK Communications.

Pursuant to the resolution of its board of directors on November 24, 2016, SK Communications entered into a comprehensive share exchange agreement with SK Telecom on November 25, 2016. Upon the consummation of the share exchange on February 7, 2017, SK Communications became a wholly-owned subsidiary of SK Telecom.

[PS&Marketing]

On February 20, 2014, the board of directors of PS&Marketing resolved to acquire the retail distribution business, including related assets, liabilities, contracts and human capital of the information technology and mobile wing of SK Networks. On the same day, the board of directors of PS&Marketing also resolved to acquire retail stores, including their assets and liabilities, of LCNC Co., Ltd (“LCNC”). The acquisitions were completed on April 30, 2014 at a purchase price of Won 124.5 billion for the assets acquired from SK Networks and a purchase price of Won 10 billion for the assets acquired from LCNC.

[NSOK]

On March 31, 2015, NSOK acquired the unmanned electronic security business of Joeun Safe to expand its unmanned security business The acquisition cost, which had been reported on January 5, 2015 as Won 19.4 billion, was subject to adjustment depending on the customer transfer rate. The final acquisition cost was determined to be Won 16.9 billion.

[Iriver]

Pursuant to the resolution of its board of directors on November 18, 2014, Iriver decided to merge with Iriver CS, its wholly-owned subsidiary, with Iriver as the surviving entity. The merger was completed based on the merger ratio of 1:0 with no capital increase. The merger and merger registration were completed on January 31, 2015 and February 2, 2015, respectively.

15

Pursuant to the resolution of its board of directors on July 17, 2017, Iriver approved a contract to acquire a total of 1,000,000 shares of S.M. Life Design Company Japan Inc. (a 100% equity interest) from S.M. Entertainment Japan Co., Ltd. with the purposes of entering foreign markets and maximizing business synergy. Iriver acquired control of S.M. Life Design Company Japan Inc. upon its completion of payment for the shares on September 1, 2017.

Pursuant to the resolution of its board of directors on July 17, 2017, Iriver decided to merge with S.M. Mobile Communications JAPAN Inc., a contents and information distribution company, with the purpose of reinforcing its contents based device business and enhancing managerial efficiency. As of October 1, 2017, Iriver merged S.M. Mobile Communications JAPAN Inc. into it with a merger ratio of 1:1.6041745, based on which Iriver issued 4,170,852 new common shares.

On February 23, 2018, the Company acquired 414,000 additional shares (a 55.8% equity interest) of Groovers Co., Ltd. (“Groovers”), which provides high quality sound services such as FLAC (Free Lossless Audio Codec), MQS (Mastering Quality Sound) and DSD (Direct Stream Digital) from NHN Bugs Corp. and individuals. As a result, the Company acquired control of Groovers as its equity interest therein increased from 44.2% to 100%.

On February 28, 2018, the Company entered into an agreement with S.M. Entertainment Co., Ltd. to acquire supply and distribution rights for music and digital contents of S.M. Entertainment Co., Ltd., JYP Entertainment Corporation and Big Hit Entertainment. Through this arrangement, the Company plans to increase sales by entering the music and sound recording industries and to create synergies through strategic alliances.

In order to achieve management efficiency and maximize organizational operation synergies, groovers Japan Co., Ltd. and SM Mobile Communications Japan Inc., each of which is a Japanese subsidiary of the Company, completed their merger with groovers Japan Co., Ltd. as the surviving entity, effective as of July 1, 2018.

On July 26, 2018, the board of directors of the Company resolved to make an equity investment of Won 11,000 million (2,200,000 common shares) in Groovers for the purposes of providing operating funds to improve its financial structure and pursue new businesses. Payment was completed on July 27, 2018, and the Company’s ownership interest after such equity investment is 100%.

On August 31, 2018, pursuant to the resolutions of its board of directors and the extraordinary meeting of shareholders, each of which was held on June 28, 2018, Groovers acquired all properties, assets and rights related to the Music Mate streaming service from SK TechX for Won 3,570 million.

[SK M&Service]

Pursuant to the resolutions of its board of directors and its extraordinary shareholders meeting held on May 29, 2017, SK M&Service decided to acquire SK Planet’s BENEPIA business (including agency service for the Flexible Benefit Plan and related tangible and intangible assets, goodwill, systems, etc.) for Won 7.5 billion on July 1, 2017.

16

[SK Telecom]

(1) Issuance of bonds

On May 14, 2014, the Company issued four tranches of fixed-rate unsecured bonds in the principal amounts of Won 50 billion (with an annual interest rate of 3.301% and a maturity date of May 14, 2019), Won 150 billion (with an annual interest rate of 3.637% and a maturity date of May 14, 2024), Won 50 billion (with embedded options, an annual interest rate of 4.725% and a maturity date of May 14, 2029), and Won 50 billion (with embedded options, an annual interest rate of 4.72% and a maturity date of May 14, 2029).

On October 28, 2014, the Company issued three tranches of fixed-rate unsecured bonds in the principal amounts of Won 160 billion (with an annual interest rate of 2.53% and a maturity date of October 28, 2019), Won 150 billion (with an annual interest rate of 2.66% and a maturity date of October 28, 2021), and Won 190 billion (with an annual interest rate of 2.82% and a maturity date of October 28, 2024).

On February 26, 2015, the Company issued three tranches of fixed-rate unsecured bonds in the principal amounts of Won 100 billion (with an annual interest rate of 2.40% and a maturity date of February 26, 2022, Won 150 billion (with an annual interest rate of 2.49% and a maturity date of February 26, 2025), and Won 50 billion (with an annual interest rate of 2.61% and a maturity date of February 26, 2030).

On July 17, 2015, the Company issued four tranches of fixed-rate unsecured bonds in the principal amounts of Won 90 billion (with an annual interest rate of 1.89% and a maturity date of July 17, 2018), Won 70 billion (with an annual interest rate of 2.66% and a maturity date of July 17, 2025), Won 90 billion (with an annual interest rate of 2.82% and a maturity date of July 17, 2030), and Won 50 billion (with an annual interest rate of 3.40% and a maturity date of July 17, 2030).

On November 30, 2015, the Company issued four tranches of fixed-rate unsecured bonds in the principal amounts of Won 80 billion (with an annual interest rate of 2.073% and a maturity date of November 30, 2018), Won 100 billion (with an annual interest rate of 2.550% and a maturity date of November 30, 2025), Won 70 billion (with an annual interest rate of 2.749% and a maturity date of November 30, 2035), and Won 50 billion (with embedded options, an annual interest rate of 3.100% and a maturity date of November 30, 2030).

On March 4, 2016, the Company issued four tranches of fixed-rate unsecured bonds in the principal amounts of Won 70 billion (with an annual interest rate of 1.651% and a maturity date of March 4, 2019), Won 100 billion (with an annual interest rate of 1.802% and a maturity date of March 4, 2021), Won 90 billion (with an annual interest rate of 2.077% and a maturity date of March 4, 2026), and Won 80 billion (with an annual interest rate of 2.243% and a maturity date of March 4, 2036).

On June 3, 2016, the Company issued four tranches of fixed-rate unsecured bonds in the principal amounts of Won 50 billion (with an annual interest rate of 1.621% and a maturity date of June 3, 2019), Won 50 billion (with an annual interest rate of 1.709% and a maturity date of June 3, 2021), Won 120 billion (with an annual interest rate of 1.973% and a maturity date of June 3, 2026), and Won 50 billion (with an annual interest rate of 2.172% and a maturity date of June 3, 2031).

On April 25, 2017, the Company issued four tranches of fixed-rate unsecured bonds in the principal amounts of Won 60 billion (with an annual interest rate of 1.925% and a maturity date of April 25, 2020), Won 120 billion (with an annual interest rate of 2.168% and a maturity date of April 25, 2022), Won 100 billion (with an annual interest rate of 2.552% and a maturity date of April 25, 2027), and Won 90 billion (with an annual interest rate of 2.649% and a maturity date of April 25, 2032).

On November 10, 2017, the Company issued three tranches of fixed-rate unsecured bonds in the principal amounts of Won 100 billion (with an annual interest rate of 2.388% and a maturity date of November 10, 2020), Won 80 billion (with an annual interest rate of 2.634% and a maturity date of November 10, 2022), and Won 100 billion (with an annual interest rate of 2.840% and a maturity date of November 10, 2027).

17

On February 20, 2018, the Company issued four tranches of fixed-rate unsecured bonds in the principal amounts of Won 110 billion (with an annual interest rate of 2.572% and a maturity date of February 20, 2021), Won 100 billion (with an annual interest rate of 2.806% and a maturity date of February 20, 2023), Won 200 billion (with an annual interest rate of 3.004% and a maturity date of February 20, 2028) and Won 90 billion (with an annual interest rate of 3.016% and a maturity date of February 20, 2038).

On April 16, 2018, the Company issued fixed-rate U.S. dollar-denominated bonds in the principal amount of US$500 million (with an annual interest rate of 3.75% and a maturity date of April 16, 2023).

On September 17, 2018, the Company issued three tranches of fixed-rate unsecured bonds in the principal amounts of Won 100 billion (with an annual interest rate of 2.098% and a maturity date of September 17, 2021), Won 150 billion (with an annual interest rate of 2.330% and a maturity date of September 17, 2023) and Won 50 billion (with an annual interest rate of 2.436% and a maturity date of September 17, 2038).

In 2018, the Company issued an aggregate of Won 400 billion principal amount of hybrid securities in the form of two series of unguaranteed subordinated bonds, Won 300 billion of which have an annual interest rate of 3.70% and Won 100 billion of which have an annual interest rate of 3.65%. Both of such interest rates are based on the five-year Korean government bond yield plus a spread. For both series of the hybrid securities, an additional spread of 0.25% is payable beginning ten years from the date of issuance and an additional spread of 0.75% is payable after 25 years from the date of issuance. The Company classified the hybrid securities as equity, as there is no contractual obligation to deliver financial assets to the bondholders. The hybrid securities are subordinated bonds which take priority over common shares upon bankruptcy or liquidation. The maturity date of the hybrid securities is June 7, 2078, which can be extended by the Company without any notice or announcement.

[SK Broadband]

SK Broadband acquired subscribership of regional cable and other service providers on several different occasions. Such acquisitions were intended to secure a stable subscriber base for its broadband Internet service and, at the same time, increase the service coverage area. Because such acquisitions were conducted on a relatively small scale and involved the purchase of subscribership, SK Broadband did not believe that such acquisitions rose to the level of purchasing an entire business line from another company or were likely to have a material impact on its business, and therefore decided that such acquisitions did not require resolutions of its shareholders.

18

19

20

21

Each company in the consolidated entity is a separate legal entity providing independent services and products. The business is primarily separated into (1) the wireless business consisting of cellular voice, wireless data and wireless Internet services, (2) the fixed-line business consisting of fixed-line telephone, high speed Internet, data and network lease services, among others, and (3) other businesses consisting of platform services and Internet portal services, among others.

Set forth below is a summary business description of material consolidated subsidiaries.

22

[Wireless Business]

The telecommunications services market can be categorized into telecommunications services (such as fixed-line, wireless, leased line and value-added services) and broadcasting and telecommunications convergence services. Pursuant to the Telecommunications Business Act, the telecommunications services market can be further classified into basic telecommunications (fixed-line and wireless telecommunications), special category telecommunications (resale of telecommunications equipment, facilities and services) and value-added telecommunications (Internet connection and management, media contents and others). The size of the domestic telecommunications services market is determined based on various factors specific to Korea, including size of population that uses telecommunication services and telecommunications expenditures per capita. While it is possible for Korean telecommunication service providers to provide services abroad through acquisitions or otherwise, foreign telecommunication services markets have their own characteristics depending, among others, on the regulatory environment and demand for telecommunication services.

The Korean mobile communication market is considered to have reached its maturation stage with more than a 100% penetration rate. However, the Korean mobile communications market continues to improve in the quality of services with the help of advances in network-related technology and the development of highly advanced LTE-A, LTE and 3G smartphones which enable the provision of convergence services for multimedia contents, mobile commerce, telematics, new media and other related services. In addition, through the commercialization of LTE network in July 2011 and LTE-A network in June 2013, B2B businesses, such as the corporate “connected workforce” business which can directly contribute to an enhancement in productivity, are expected to grow rapidly.

In the first half of 2014, wideband LTE-A service was commercialized and on December 29, 2014, tri-band LTE-A service with a maximum speed of 300 Mbps was also commercialized. Since June 2017, through the commercialization of 5band CA technology, which is considered the final stage of LTE development, the Company has provided 4.5G service at the speed of 700Mbps to 900Mbps. Since early 2018, the Company was the first to start providing LTE service with a speed of up to 1 Gbps. Such achievements were the building blocks towards the Company’s LTE penetration reaching 79.3% as of September 30, 2018.

(Unit: in 1,000 persons)

The Korean mobile communication market includes the entire population of Korea with mobile communication service needs, and almost every Korean is considered a potential user. Sales revenue related to data services is expected to increase due to the increasing popularity of smartphones and high-speed wireless networks. There is also a growing importance to the business-to-business segment, which creates added value by selling and developing various solutions. Seasonal and economic fluctuations have much less impact on the Korean mobile communication market compared to other industries.

Set forth below is the historical market share of the Company.

(Unit: in percentages)

23

The Company is seeking to transform itself from a telecommunications service provider into a comprehensive ICT service provider. It has continued to innovate the scope of its services and achieved strong growth in subscribers amid fierce competition and rate cuts. As a result, for the third quarter of 2018, the Company recorded Won 4,186 billion in revenue and Won 304 billion in operating income on a consolidated basis and Won 2,926 billion in revenue and Won 311 billion in operating income on a separate basis. In particular, the number of subscribers subscribing to “Band Data” plans, which was launched in the second quarter of 2015, has continued to steadily increase in 2017, which in turn led to an increase in data usage. The success of Luna, a smartphone launched in September 2015 that was designed to run exclusively on the Company’s networks, led to the launch of various other relatively low-priced devices and became an example of successfully targeting a niche market. In July 2018, the Company changed the overall paradigm of the existing “Band Data” plans from individual plans to family plans and launched the “T Plan,” which increases the amount of data provided.

By continuing to be innovative in developing core competencies, the Company has more firmly established its position as the market leader in wireless telecommunications. The competitive environment of the wireless telecommunications industry has become more focused on retention especially through the reinforcement of marketing that is focused on innovation in increasing customer value. In the third quarter of 2018, the average monthly churn rate was 1.2%. The number of subscribers (including MVNO subscribers) as of September 30, 2018 was 30.8 million, an increase of approximately 570,000 since December 31, 2017. In particular, the number of LTE subscribers as of September 30, 2018, was 24.4 million, an increase of approximately 1,520,000 since December 31, 2017, solidifying the Company’s market leadership. In addition, the Company continued to sell products targeted towards second devices such as the Cookiz Phone, T Outdoor and T Pocket-fi.

Following the launch of commercial LTE services in July 2011, the Company became the first telecommunications service provider in the world to launch commercial wideband LTE-A services in June 2014. The Company launched tri-band LTE-A services in December 2014 and 5band 4.5G services in June 2017. In the first quarter of 2018, the Company commenced providing LTE service of up to 1 Gbps by utilizing five-band carrier aggregation technology and 4T4R technology. By launching various high quality services utilizing the LTE-A and wideband LTE networks such as group video conference call services and full high definition mobile IPTV streaming services, the Company plans to provide an innovative user experience, enhance customer satisfaction and increase profitability.

The Company has proved that it has superior network quality compared to its competitors according to the MSIT quality evaluations. The Company has also proved to be the leader in Korea’s top three customer satisfaction indices: according to the National Customer Satisfaction Index, Korean Customer Satisfaction Index and Korean Standard Service Quality Index, the Company has continued to hold the leading position for 21 years, 21 years and 19 years, respectively. The Company received the highest level of evaluation in 2017 by the Korea Commission for Corporate Partnership for the sixth consecutive year and was selected for the commission’s Honored Corporation Award, demonstrating the Company’s efforts to be fair and law-abiding in its path towards creating a New ICT ecosystem.

SK Telink, a consolidated subsidiary of the Company, expanded its operations to the MVNO business based on its technical expertise and know-how obtained in its international telecommunications business and launched its MVNO service, ‘SK 7Mobile,’ which is offered at reasonable rates and provides excellent quality. SK Telink is increasing its efforts to develop low-cost distribution channels and create niche markets through targeted marketing towards customers including foreign workers, middle-aged adults and students. An MVNO leases the networks of an MNO and provides wireless telecommunication services under its own brand and fee structure, without owning telecommunication networks or frequencies.

Network O&S, a subsidiary of the Company responsible for the operation of the Company’s base stations and related transmission and power facilities, offers quality fixed-line and wireless network services to customers, including mobile office products to business customers.

PS&Marketing, a subsidiary of the Company, provides a sales platform for products of the Company and SK Broadband including fixed-line and wireless telecommunication products that address customers’ needs for various convergence products. PS&Marketing provides differentiated service to clients through the establishment of new sales channels and product development.

24

[Fixed-line Business]

The Korean fixed-line services industry is marked by a relatively low level of economic sensitivity and high level of market concentration, as the government is highly selective in granting telecommunications business licenses. The competitive landscape of the fixed-line and wireless services markets is dominated by its three leading operators, the Company (including SK Broadband), KT and LG U+. Growing competition within the industry has promoted rapid technological evolution, including the convergence of fixed-line and wireless services, as well as broadcasting and telecommunications. In general, the fixed-line and wireless services markets have been characterized by relatively high profitability, cash flows and financial stability.

The high-speed Internet segment operates in a highly mature market. While the number of new operators has been decreasing, the segment has shown increasing growth centered around the premium Giga-Internet services. In the case of IPTV services, the conversion rate to digital television in the overall paid broadcasting market has been increasing, and the proportion of IPTV subscribers among high-speed Internet users has been expanding. Although the total number of new subscribers in the segment has been decreasing, the number of subscribers to premium services such as ultra-high definition broadcasting has been increasing, and the segment has recorded a high level of revenue growth due to an increase in the consumption of paid contents and the expansion of the platform business such as media advertising. In order to satisfy the diversifying needs of customers and the trend of combining or fusing services, the industry players are boosting their efforts to strengthen the competitiveness of their respective services by providing differentiated contents and incorporating AI and big data technologies. Such competition will present new growth opportunities in the home platform area in connection with the fourth industrial revolution in the future. In order to target the specialized market for the expansion of the platform business, the Company plans to continue its growth by enhancing its customer-focused marketing efforts and strengthening its platform capabilities.

(Unit: in 1,000 persons)

High-speed Internet, fixed-line telephone and IPTV services are mature markets that are comparatively less sensitive to cyclical economic changes as such services have become more of a necessity and the market has matured. The telecommunications services market overall is not expected to be particularly affected by economic downturns due to the low income elasticity of demand for telecommunication services.

Set forth below is the historical market share of the Company.

(Unit: in percentages)

25

For the third quarter of 2018, SK Broadband recorded Won 820.2 billion in revenue, Won 42.2 billion in operating income and Won 57.4 billion in profit for the period on a consolidated basis. SK Broadband’s revenue grew compared to the previous quarter and the same quarter of the previous year, driven by an increase in revenue from IPTV services due to increases in the number of subscribers and revenue from paid contents, and its non-operating profit increased due to disposition of tangible assets pursuant to the sale of the Seocho IDC. The number of subscribers to each of its high-speed Internet, residential fixed-line telephones, VoIP services and IPTV services was 5.57 million, 2.28 million, 1.69 million and 4.66 million, respectively (resulting in the total number of telephone subscribers being 4.01 million subscribers).

In the case of high-speed Internet, SK Broadband has continued to increase the proportion of subscribers of premium services, including its Giga Internet service, to approximately 32% and thereby enhance the composition of its customers, by strengthening its marketing efforts based on quality and customer value improvements. With the launch of its 2.5 Giga Internet service and the future launch of a 10 Giga Internet service, SK Broadband seeks to lay the foundation for an Internet service environment that can provide new value to its customers.

With continued increase in the number of subscribers and growth in revenue from paid contents, SK Broadband’s IPTV service business continued its steady growth, with revenue for the third quarter of 2018 increasing by more than 20% compared to the third quarter of 2017. In particular, SK Broadband achieved record quarterly revenue from its paid contents business, due mainly to the contents recommendation solutions and diversification of product packaging. With the launch of the “live fairy tale” service for children based on highly immersive augmented reality technology and the commercialization of a new user interface that facilitates the use and search of contents for customers, the Company has continued to improve the competitiveness of its contents and services. SK Broadband will continue to enhance customer utility with new services and provide differentiated value to its customers through various marketing efforts in the future.

The number of Oksusu subscribers and users has continued to increase due to marketing centered on sports programs, such as professional baseball and the Asian Games. Oksusu continued to enhance its services for increased customer satisfaction, such as removing commercials from sports broadcasting and improving video quality and transmission methods with the implementation of new technologies. SK Stoa boosted its revenue and volume growths by strengthening mobile sales through the addition of partnered channels and expanding the direct purchase of high-quality products.

SK Telink, a provider of international telecommunications service, has been able to establish itself as a market leader as a result of its affordable pricing, proactive marketing and the quality of its services. It launched a mobile phone-based international calling service under the brand name “00700” in 1998, creating a new niche market within the long-distance telephony market that was otherwise dominated by existing service providers. In 2003, SK Telink was designated a common carrier for international calling services, which allowed the Company to expand its international calling services to fixed-line international calling services. In 2005, SK Telink obtained a license to operate VoIP services and local calling value-added services to develop into a versatile fixed-line telecommunications service provider. SK Telink plans to strategically target the convergence of wireless and fixed-line telecommunications and strengthen its existing business as a comprehensive ICT service provider, including international satellite calling services (Internet, wireless and fixed-line calling services on ships, aircraft and in polar regions), and video conference call services while aiming to satisfy the diverse needs of customers by providing quality solutions at reasonable prices.

[Other Business]

As the number of smartphones distributed in Korea exceeds 40 million, the growth in various mobile devices has spurred the rise of the service provider with a strong platform business as the leader in the ICT market. It is becoming increasingly important to enhance competitiveness by building a platform with large data capacity to handle the increase in data transmission.

26

A platform business acts as an intermediary by promoting interactions among various customer groups, thereby generating new values. It is important for a platform business to continually attract subscribers and users and to create an ecosystem with certain lock-in effects. A platform can exist in various forms, including as a technological standard (iOS, Android OS), a subscriber-based service platform (Facebook, Twitter) or a marketplace (Amazon, Onestore). Platform businesses are evolving and expanding globally.

A platform business has strong growth potential due to its connectivity with related services and ease of global expansion. Apple became a world-leading smartphone producer based on its innovative design and the competitive strength of its App Store platform. Google has created a new ecosystem of long-tail advertising by attracting millions of third parties to its advertising platform, as well as showing strong growth in mobile markets with its competitive platform based on Android OS. It is becoming increasingly important to enhance competitiveness through a database that can register and analyze purchase patterns of customers across all areas and a platform with large data capacity with which to utilize this database and provide differentiated services to customers.

The scope and value generated by the platform business, including application and content marketplaces and N-screen services, continue to increase as smartphones and tablet computers become more popular and the bandwidth and speed of network infrastructure improve. As the wireless network evolves to LTE, business opportunities for the platform business exist, including multimedia streaming, N-screen service based on cloud technology and high-definition location-based services. Since the platform business realizes profit by connecting with advertisements or commerce sites after building a critical mass of subscribers and traffic, the recent growth in the advertising and commerce markets is expected to present an opportunity for platform businesses. The importance of building a platform with large data capacity that is connected to various digital contents and commerce is expected to increase in the future.

The Company expects that mobile-centered online commerce markets will continue to grow due to the growth potential of the Internet shopping population, the strengthening of online business models by off-line operators, and the continued rapid rise of mobile commerce. As various lifestyle services beyond goods are expanding as a new field in the commerce market industry, new business models continue to emerge and spread.

The growth of application marketplaces, which started with Apple’s App Store, provides the platform business with new opportunities for revenue generation. The competitive paradigm is shifting from a competition among platform operators toward a competition among eco-systems that include application developers as well as platform operators.

The Company plans to expand its platform ecosystem in operating its commerce business which includes marketplace and O2O businesses, such as 11st, Syrup and OK Cashbag, thereby ultimately increasing its enterprise value.

11st, an online marketplace, has continued its growth through effective marketing and customer satisfaction. Despite its later entry into the online commerce market (launched in 2008) which was already divided between Auction and G-Market, it is leading the domestic e-commerce market. Furthermore, 11st has established itself as the domestic market leader in mobile commerce, following its successful entry into and rapid growth in this market.

OK Cashbag is a point-based loyalty marketing program which has grown to become a global top-tier loyalty marketing program since its inception in 1999. Customers have access to increased benefits through accumulation of loyalty reward points and partner companies use OK Cashbag as a marketing resource. As Korea’s largest loyalty mileage program, OK Cashbag maintains a leading position in the industry. The Company is continuing to develop its service in light of market conditions and customers’ needs to enhance its customers’ perception of point value and is reviewing and pursuing various plans to develop OK Cashbag into a service that goes beyond a mileage program that leverages the key competitiveness of OK Cashbag such as its platform and partnership network.

27

Syrup is a consumer-oriented commerce service with the goal of minimizing its customers’ time and efforts while maximizing the economic benefits by providing information about coupons and events based on time, place and occasion. To achieve this goal, Syrup combines location-based services, such as geo-fencing, a virtual perimeter technology using a global positioning system (or, GPS) and Bluetooth Low Energy (or, BLE), with big data analysis of consumption patterns. Syrup’s business partners can benefit from cost-effective marketing through Syrup by utilizing statistics and analysis regarding consumers’ frequency of visits, preferred products, and consumption patterns.

T-Map Navigation provides map, local information, real-time traffic information and navigation services. T-Map Navigation is one of the leading location-based service platforms in Korea. By entering the Online to Offline service area with T map Taxi, T map Public Transportation and others, the Company is expanding its mobile platform foundation that connects day to day life. In September 2016, the Company launched T-Map x NUGU, which provides a new form of intelligent car infortainment service in collaboration with the Company’s artificial intelligence (“AI”) service, NUGU. The Company has continued to secure subscribers by differentiating its product T-map x NUGU as a unique “artificial intelligence driving assistant.” The Company has also focused on providing effective “info-tainment” platforms to commercial vehicle businesses as well as providing localized content, including region-specific information and advertisements. The Company plans to further develop the T-Map Navigation platform by initiating open application programming interface-based services, providing services to more diverse types of devices and providing local area-based services.

Onestore, an application platform launched in 2016 through a joint venture between SK Telecom, KT, LG U+ and Naver’s app store, launched Onestore 2.0, which showcases the particular benefits of the application platform. The Company intends to further develop Onestore into a personalized gateway and mobile playground through enhanced product and brand competitiveness, expansion of the scope of serviceable devices, reinforcement of digital content offerings and enhancement of search services, among other things.

The Company’s instant messenger service, “Nate-On,” had a market share of 11.7% in the instant messenger market in Korea with 2.1 million net users during the month of September 2018. “Nate,” the Company’s Internet search portal service, realized a page-view market share of 3.7% as of September 30, 2018. (Source: Korean Click, based on fixed-line access)

(Unit: in millions of Won and percentages)

28

[Wireless Business]

As of September 30, 2018, based on the Company’s standard monthly subscription plan, the basic service fee was Won 12,100 and the usage fee was Won 1.98 per second.

[Fixed-line Business]

SK Broadband provides broadband Internet access service, telephony, TV, corporate business services and other services for both individual and corporate customers. As of September 30, 2018, SK Broadband’s revenue (on a consolidated basis) comprised of 25.8% broadband Internet, 2.1% home telephony services, 31.7% corporate business services, 38.4% TV services and 2.0% other telecommunications services. Price fluctuations in the different services provided by SK Broadband are due to discounts provided for long term contracts, changes in equipment costs and competition between companies.

[Other Business]

Set forth below are major products and services of the Company’s material consolidated subsidiaries.

[Wireless Business]

(Unit: in 100 millions of Won)

(Unit: in 100 millions of Won)

29

[Fixed-line Business]

In 2018, the Company plans to make a similar level of capital expenditures to expand network coverage and upgrade its media platform compared to 2017, but does not expect such expenditures to have a material adverse effect on the Company’s financial structure through improvements in investment efficiency.

(Unit: in 100 millions of Won)

(Unit: in millions of Won)

30

(Unit: in millions of Won)

Currency swap contracts under cash flow hedge accounting as of September 30, 2018 are as follows:

31

As of September 30, 2018, fair values of the above derivatives recorded in assets or liabilities and details of derivative instruments were as follows:

(Unit: in millions of Won; in thousands of foreign currencies)

[SK Telecom]

Not applicable.

[SK Broadband]

Due to the nature of the telecommunication service business, SK Broadband has entered into agreements related to the joint usage of telecommunication facilities for interconnection among telecommunication lines conduits and telecommunication service providers. Below are the major contracts of SK Broadband. In addition to the below, SK Broadband has also entered into various real estate rental agreements.

32

[SK Communications]

Set forth below are the Company’s R&D expenditures.

33

The Company manages its corporate brand and other product brands in a comprehensive way to protect and increase their value. The Company’s Brand Management Council in charge of overseeing its systematic corporate branding operates full-time to execute decisions involving major brands and operates ‘Comm.ON,’ an intranet system to manage the development, registration and licensing of brands.

[SK Telecom]

As of September 30, 2018, the Company held 4,822 Korean-registered patents and 1,415 foreign-registered patents. The Company holds 725 Korean-registered trademarks and owns intellectual property rights to its proprietary graphic design of the alphabet “T” representing its brand. The designed alphabet “T” is registered in all business categories for trademarks (total of 45). The number of registered patents and trademarks is subject to constant change due to the acquisition of new rights, expiration of terms, abandonments and dispositions.

[SK Broadband]

As of September 30, 2018, SK Broadband held 348 Korean-registered patents and 150 foreign-registered patents (including those held jointly with other companies). It also holds 326 Korean-registered trademarks and owns intellectual property rights to its proprietary graphic design of the alphabet “B” representing its brand. The designed alphabet “B” is registered in all business categories for trademarks (total of 45). The number of registered patents and trademarks is subject to continual change due to the acquisition of new rights, expiration of terms, abandonments and dispositions.

[SK Planet]

As of September 30, 2018, SK Planet held 2,459 registered patents, 123 registered design marks, 1,050 registered trademarks and 4 copyrights (including those held jointly with other companies) in Korea. It also holds 202 U.S.-registered patents, 116 Chinese-registered patents, 79 Japanese-registered patents, 60 E.U.-registered patents (all including patents held jointly with other companies) and 281 registered trademarks, along with a number of other intellectual property rights, in other countries.

[SK Communications]

As of September 30, 2018, SK Communications held 93 registered patents, 26 registered design rights and 506 registered trademarks in Korea.

The Company does not engage in any manufacturing and therefore does not undertake any industrial processes that emit pollutants into the air or industrial processes in which hazardous materials are used.

34

III. FINANCIAL INFORMATION

Below is the summary consolidated financial information of the Company as of September 30, 2018, December 31, 2017 and December 31, 2016 and for the nine months ended September 30, 2018 and 2017 and the years ended December 31, 2017 and 2016. The Company’s unaudited consolidated financial statements as of September 30, 2018 and December 31, 2017 and for the nine months ended September 30, 2018 and 2017, which are prepared in accordance with K-IFRS, are attached hereto.