UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): December 6, 2012

Constellation Energy Partners LLC

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (832) 308-3700

Not applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Item 7.01 Regulation FD Disclosure.

On December 6, 2012, Constellation Energy Partners LLC (the “Company”) issued a press release announcing that it has withdrawn Proposal Nos. 2 and 3 in the Company’s proxy statement from consideration at the Company’s annual meeting currently scheduled for December 14, 2012, that would have facilitated an election by the Company to be treated as a corporation rather than a partnership for income tax purposes. The decision to withdraw the proposals comes after the Company received a Class A Unitholder Ballot on November 30, 2012 from Constellation Energy Partners Management, LLC (“CEPM”) indicating an election to vote all of the Class A units against both proposals. CEPM is a wholly owned affiliate of PostRock Energy Corporation.

A copy of the press release is furnished and attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated into this Item 7.01 by reference.

In accordance with General Instruction B.2 of Form 8-K, the information set forth in this Item 7.01 and in Exhibit 99.1 shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, unless the Company specifically states that the information is to be considered “filed” under the Exchange Act or incorporates it by reference into a filing under the Exchange Act or the Securities Act of 1933, as amended.

Item 9.01 Financial Statements and Exhibits.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

EXHIBIT INDEX