13D Filing: Monarch Alternative Capital and Resolute Energy Corp (REN)

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934*

(Amendment No. 1)

Resolute
Energy Corporation

(Name of Issuer)

Common Stock, par value $0.0001

(Title of Class of Securities)

76116A306

(CUSIP Number
of Class of Securities)

Michael Kelly, Esq.

Monarch Alternative Capital LP

535 Madison Avenue

New
York, NY 10022

Telephone: (212) 554-1700

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

Copies to:

Mark
Cognetti, Esq.

Michael Brandt, Esq.

Willkie Farr & Gallagher LLP

787 Seventh Avenue

New
York, NY 10019-6099

(212) 728-8000

February 8, 2018

(Date
of Event which Requires Filing of this Schedule)

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 §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-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 240.13d-7 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, as amended (the 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

SCHEDULE 13D

SCHEDULE 13D

Pursuant to Rule 13d-2 promulgated under the Act, this Amendment No. 1 to Schedule 13D (this
Amendment No. 1) is being filed with respect to the common stock par value $0.0001 per share (Common Stock), of Resolute Energy Corporation (the Issuer), to amend the Schedule 13D filed
on January 26, 2018 (the Original 13D and, as amended by this Amendment No. 1, the Schedule 13D). Capitalized terms used but not otherwise defined herein shall have the meanings ascribed to them in the
Original 13D.

Item 4 of this Schedule 13D is hereby amended to include the following:

Following discussions with the Issuer after its receipt of the January Letter, the Reporting Persons continue to believe that changes to
the Board are necessary to maximize stockholder value. As a result, on February 8, 2018, an affiliate of the Reporting Persons delivered a nomination notice (the Nomination Notice) to the Issuer which is attached as Exhibit
99.3 to this Schedule 13D, nominating three highly qualified individuals, Patrick Bartels, Joseph Citarrella and Samuel Langford (collectively, the Nominees), for election to the Board at the Issuers 2018 annual meeting of
stockholders (the Annual Meeting).

The Reporting Persons believe that the Nominees have the qualifications, experience
and skill sets that will make them valuable additions to the Board.

The Reporting Persons have engaged, and may continue to engage, in
discussions with the Issuer regarding Board representation and the composition of the Issuers Board, generally.

The Nomination
Notice also includes a notice to the Issuer that the Reporting Persons intend to submit, for a stockholder vote at the Annual Meeting, a resolution that would repeal any provision of the Bylaws of the Issuer in effect at the time of the Annual
Meeting that was not included in the Bylaws of the Issuer in effect as of February 8, 2018 and as publicly filed with the Securities and Exchange Commission (the SEC) prior to February 8, 2018.

Item 5(a)-(c) of this Schedule 13D is hereby amended
and restated to read as follows:

(a) Each of MAC, MDRA GP and Monarch GP indirectly beneficially own 2,193,400 shares of Common Stock.
Such shares represent 9.75% of the 22,503,907 common shares outstanding as of October 31, 2017, according to the Form 10-Q filed by the Issuer with the SEC on November 6, 2017. None of the individual Funds beneficially own a number of
shares of Common Stock representing more than 5% of the outstanding shares of Common Stock.

(b) MAC, MDRA GP and Monarch GP share voting
and dispositive power over 2,193,400 shares of Common Stock with each applicable Fund directly holding such shares, except for 100 of such shares, which the Funds hold indirectly through

affiliated entities.

(c) Schedule I hereto sets forth all transactions with respect to the Common Stock effected by
the Reporting Persons since the date of the Original 13D. All such transactions were effected in the open market, and per share prices include any commissions paid in connection with such transactions.

Item 6 of this Schedule 13D is hereby amended to include the following:

On February 6, 2018, Monarch Energy Holdings LLC, an affiliate of the Reporting Persons (MEH), entered into a
Nomination Agreement with Samuel Langford (the Nomination Agreement). Pursuant to such agreement, MEH has agreed to indemnify Mr. Langford for certain potential claims in connection with his standing as a candidate for
election to the Board. MEH has also agreed to reimburse Mr. Langford for reasonable and documented out-of-pocket travel and related expenses, subject to a certain cap, incurred by Mr. Langford in connection with his service as a Nominee.
The foregoing description of the Nomination Agreement is not complete and is qualified in its entirety by reference to the Nomination Agreement attached as Exhibit 99.4 to this Schedule 13D, which is incorporated herein by reference.

Except as disclosed in this Schedule 13D, there are no contracts, arrangements, understandings or relationships with respect to securities of
the Issuer.

Item 7 of this Schedule 13D is hereby amended to add the
following exhibits:

[Signatures on following page]

SIGNATURES

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

SCHEDULE I