UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934*

(Amendment No. 3)

Platinum Group Metals Ltd.

(Name of Issuer)

Common Shares, No Par Value

(Title of Class of Securities)

72765Q601

(CUSIP Number)

COPY TO:

Joshua Beiser

Senior Investment Counsel

Liberty Mutual Insurance

175 Berkeley Street

Boston, MA 02116

Tel: 617-357-9500

(Name, Address and Telephone Number of Persons Authorized to Receive Notices and Communications)

May 15, 2018

(Dates of Events which Require Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box    ☐

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7(b) for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

*consists of 36,160,609 shares of common stock and 20,000,000 warrants

**percentage based on total common shares and warrants currently held on a partially diluted basis

Liberty Metals & Mining Holdings, LLC (“LMMH”) hereby amends the report on Schedule 13D filed with the Commission on January 10, 2013 (the “Schedule 13D”), as it has been amended from time to time, with respect to the shares of common stock, no par value, of Platinum Group Metals Ltd. (the “Issuer” or “Platinum Group”).

Capitalized terms used by not defined herein have the meaning assigned to them in the Schedule 13D.

Item 1. Security and Issuer

The principal executive offices of the Issuer has been amended to Suite 788, 550 Burrard Street, Vancouver, British Columbia, Canada, V6C 2B5.

Item 2. Identity and Background

Item 2 is amended with respect to Schedule A, updating the Executive Officers and Directors of LMMH, Liberty Mutual Insurance Company and Liberty Mutual Holding Company Inc.

Item 3. Source and Amount of Funds or Other Consideration

Item 3 of Schedule 13D is hereby amended by adding the following paragraph immediately following the last paragraph of Item 3.

LMMH acquired shares in a public offering by Issuer pursuant to a prospectus on SEC Form F-10, dated October 14, 2016, as supplemented on May 14, 2018 (the “Registration Statement”) which offering was comprised of one common share and one full common share purchase warrant. The common shares were acquired at a price of US$0.15 per share for a total purchase price for the shares acquired by LMMH in such public offering of approximately US$3,000,000.00.

LMMH also acquired 20,000,000 warrants in said offering. Each whole common share purchase warrant will be exercisable for a period of 18 months after the May 15, 2018 closing date at an exercise price of US$0.17 per share.

Item 4. Purpose of Transaction

No Modification.

Item 5. Interest in Securities of the Issuer

Item 5 is amended and restated as follows:

(b)    LMMH has the sole power to vote or direct the vote of, and the sole power to dispose or direct the disposition of, 36,160,609 Common Shares in addition to the 20,000,000 Warrants exercisable at LMMH’s discretion. LMMH has no shared power to either vote or dispose of the shares.

(c)     During the 60 days preceding the date of this report, the Reporting Person purchased the following shares of the Issuer’s Common Shares pursuant to the public offering described in Item 3 above:

(d)    With respect to LMMH, to the best of its knowledge, no other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceedings from the sale of, such securities, where such interest relates to either more or less than five percent of the class.

(e)    Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer

None.

Item 7. Material to be Filed as Exhibits    

None.

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

SCHEDULE A

Controlling Persons

Liberty Metals & Mining Holdings, LLC, is a Delaware, member-managed, limited liability company. Liberty Mutual Insurance Company, its sole member, is a Massachusetts stock insurance company which is an indirect subsidiary of Liberty Mutual Holding Company Inc., a Massachusetts mutual holding company. Liberty Mutual Holding Company Inc. is the ultimate controlling person of Liberty Metals & Mining Holdings, LLC. Liberty Mutual Holding Company Inc. is a mutual holding company wherein its members are entitled to vote at meetings of the company. No such member is entitled to cast 10% or more of the votes. Liberty Mutual Holding Company Inc. has issued no voting securities.

The director and officer information for Liberty Metals & Mining Holdings, LLC, Liberty Mutual Insurance Company and Liberty Mutual Holding Company Inc. is as follows:

Liberty Metals & Mining Holdings, LLC

175 Berkeley Street

Boston, Massachusetts 02116

Executive Officers

Liberty Mutual Insurance Company

175 Berkeley Street

Boston, Massachusetts 02116

Executive Officers

Directors

Executive Officers and Directors of Ultimate Control Person

Liberty Mutual Holding Company Inc.

175 Berkeley Street

Boston, Massachusetts 02116

Executive Officers

Liberty Mutual Holding Company Inc.

175 Berkeley Street

Boston, Massachusetts 02116

Directors