UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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): November 17, 2014

Endeavour International Corporation

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (713) 307-8700

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.

As previously announced, on October 10, 2014, Endeavour International Corporation (the “Company”) and certain of its subsidiaries (such subsidiaries, together with the Company, the “Debtors”), filed voluntary petitions for relief under chapter 11 of the United States Bankruptcy Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the District of Delaware (the “Bankruptcy Court”) in the proceeding In re Endeavour Operating Corporation, et al., Case No. Case No. 14–12308.

On November 17, 2014, the Debtors filed with the Bankruptcy Court a proposed Joint Chapter 11 Plan of Reorganization (the “Proposed Plan”) and related disclosure statement (the “Disclosure Statement”). The Proposed Plan is subject to acceptance by the Debtors’ creditors (as and to the extent required under the Bankruptcy Code) and confirmation by the Bankruptcy Court. Information contained in the Proposed Plan and the Disclosure Statement is subject to change, whether as a result of amendments to the Proposed Plan, third-party actions, or otherwise. Copies of Proposed Plan and Disclosure Statement, as filed, are attached hereto as Exhibit 99.1 and Exhibit 99.2, respectively.

This Current Report on Form 8-K is not intended to be, nor should it be construed as, a solicitation for a vote on the Proposed Plan. The Bankruptcy Court has not yet approved the Disclosure Statement as containing adequate information pursuant to section 1125(b) of title 11 of the United States Bankruptcy Code for use in the solicitation of acceptances or rejections of the Proposed Plan. Accordingly, the filing and dissemination of the Disclosure Statement are not intended to be, and should not in any way be construed as, a solicitation of votes on the Proposed Plan, nor should the information contained in the Disclosure Statement be relied on for any purpose until a determination by the Bankruptcy Court that the Disclosure Statement contains adequate information.

Cautionary Note Regarding Forward-Looking Statements

Certain statements and information included herein may constitute “forward-looking statements,” as such term is defined in Section 21E of the Securities Exchange Act of 1934, as amended, relating to future events and the financial performance of the Company. Such statements are only predictions and involve risks and uncertainties, resulting in the possibility that actual events or performance will differ materially from such predictions as a result of certain risk factors. As such, readers are cautioned not to place undue reliance on forward-looking statements, which speak only to management’s plans, assumptions and expectations as of the date hereof. Please refer to the Company’s Annual Report on Form 10-K for year ended December 31, 2013, filed with the SEC on March 17, 2014, Form 10-K/A filed with the SEC on March 21, 2014 and other filings for a discussion of material risk factors. The Company disclaims any duty to update or alter any forward-looking statements, except as required by applicable law.

Item 9.01 Financial Statements and Exhibits.

(d) 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