SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

o

Rule 13d-1(b)

x

Rule 13d-1(c)

o

Rule 13d-1(d)

CUSIP No. 04930A104

1.

Name of Reporting Person.
I.R.S. Identification No. of Above Person (Entities Only).

ING Groep N.V.

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

o

3.

SEC Use Only

4.

Citizenship or Place of Organization
The Netherlands

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With:

5.

Sole Voting Power
0

6.

Shared Voting Power
2,855,073 (1)

7.

Sole Dispositive Power
0

8.

Shared Dispositive Power
2,855,073 (1)

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
2,855,073

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o

11.

Percent of Class Represented by Amount in Row (9)
5.56% (2)

12.

Type of Reporting Person (See Instructions)
HC

CUSIP No. 04930A104

1.

Name of Reporting Person.
I.R.S. Identification No. of Above Person (Entities Only).

ING Capital Markets LLC

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

o

3.

SEC Use Only

4.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With:

5.

Sole Voting Power
0

6.

Shared Voting Power
2,855,073

7.

Sole Dispositive Power
0

8.

Shared Dispositive Power
2,855,073

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
2,855,073

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o

11.

Percent of Class Represented by Amount in Row (9)
5.56% (2)

12.

Type of Reporting Person (See Instructions)
OO

Item 1(a).

Name of Issuer:

Atlas Energy, L.P.

Item 1(b).

Address of Issuer’s Principal Executive Offices:

Park Place Corporate Center

One 1000 Commerce Drive

4TH Floor Pittsburgh PA 15275

United States of America

Item 2(a).

Name of Person Filing:

ING Groep N.V.

ING Capital Markets LLC

Item 2(b).

Address of Principal Business Office or, if none, Residence:

ING Groep N.V.

Bijlmerplein 888

1102 MG

Amsterdam-Zuidoost

Postbus 1800

1000 BV Amsterdam

The Netherlands

ING Capital Markets LLC

1013 Centre Road

Wilmington, New Castle

DE 19805

United States

Item 2(c).

Citizenship:

ING Groep N.V. – The Netherlands

ING Capital Markets LLC – Delaware

Item 2(d).

Title of Class of Securities:

Common units representing limited partnership interests of Atlas Energy, L.P.

Item 2(e).

CUSIP Number:

04930A104

Item 3.

If this statement is filed pursuant to Rule 13d-1(b), 13d-2(b) or (c), check whether the person filing is a:

(a)

o

Broker or dealer registered under section 15 of the Exchange Act.

(b)

o

Bank as defined in section 3(a)(6) of the Exchange Act.

(c)

o

Insurance company as defined in section 3(a)(19) of the Exchange Act.

(d)

o

Investment company as defined under section 8 of the Investment Company Act.

(e)

o

An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E).

(f)

o

An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F).

(g)

o

A parent holding company or control person in accordance with §240.13d-1(b)(1)(ii)(G).

(h)

o

A savings association as defined in section 3(b) of the Federal Deposit Insurance Act.

(i)

o

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act.

(j)

o

Group, in accordance with §240.13d-1(b)(1)(ii)(J).

Not Applicable.

Item 4.

Ownership:

(a)

ING Groep N.V. may be deemed to be the beneficial owner of 2,855,073 common units held by ING Capital Markets LLC, an indirect wholly owned subsidiary. ING Capital Markets LLC may be deemed the beneficial owner of all 2,855,073 common units.

(b)

ING Groep N.V. and ING Capital Markets LLC, an indirect wholly owned subsidiary of ING Groep N.V., may be deemed to be the beneficial owner of 5.56% of the common units based on 51,354,822 common units issued and outstanding as of November 1, 2012, as reported by the issuer in its Quarterly Report on Form 10-Q, as filed with the Securities and Exchange Commission on November 8, 2012.

(c)

Each of ING Groep N.V. and ING Capital Markets LLC have the shared power to vote and direct the disposition of the 2,855,073 common units held by ING Capital Markets LLC.

Item 5.

Ownership of Five Percent or Less of a Class:

Not Applicable.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person.

Not applicable.

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person.

Not Applicable.

Item 8.

Identification and Classification of Members of the Group.

Not Applicable.

Item 9.

Notice of Dissolution of Group.

Not Applicable.

Item 10.

Certification.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

ING GROEP N.V.

By:

/s/ Just A.M. Emke-Petrelluzzi Bojanic

(Signature)

J.A.M. Emke-Petrelluzzi Bojanic

Senior Compliance Officer (Name/Title)

By:

/s/ Sander Valkering

(Signature)

Sander Valkering

Business Manager (Name/Title)

ING CAPITAL MARKETS LLC

By:

/s/ Tim Casady

Tim Casady

Director (Name/Title)