13D Filing: Ares Management Llc and Gastar Exploration Inc. (NYSEMKT:GST)

CUSIP No. 36729W202

1.

Names of Reporting Persons
AF V Energy I AIV B1, L.P.

2.

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

(a)

 o

(b)

 o

3.

SEC Use Only

4.

Source of Funds (See Instructions)
OO

5.

Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)     o

6.

Citizenship or Place of Organization
Delaware

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

7.

Sole Voting Power
0

8.

Shared Voting Power
10,302,272 (See Items 3, 4, 5 and 6)

9.

Sole Dispositive Power
0

10.

Shared Dispositive Power
10,302,272 (See Items 3, 4, 5 and 6)

11.

Aggregate Amount Beneficially Owned by Each Reporting Person
10,302,272 (See Items 3, 4, 5 and 6)

12.

Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)   o

13.

Percent of Class Represented by Amount in Row (11)
5.5% (See Item 3, 4, 5 and 6)

14.

Type of Reporting Person (See Instructions)
PN