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): January 8, 2019

ANTERO MIDSTREAM PARTNERS LP

(Exact name of registrant as specified in its charter)

Delaware |  | 001-36719 |  | 46-4109058
(State or Other Jurisdiction of Incorporation) |  | (Commission File Number) |  | (IRS Employer Identification Number

1615 Wynkoop Street

Denver, Colorado 80202

(Address of Principal Executive Offices) (Zip Code)

Registrant’s Telephone Number, including Area Code (303) 357-7310

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:

x Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

Item 7.01 Regulation FD Disclosure.

On January 8, 2019, Antero Midstream Partners LP (“Antero Midstream”) and Antero Midstream GP LP (“AMGP”) issued a joint press release, a copy of which is attached hereto as Exhibit 99.1 and incorporated by reference herein, announcing Antero Midstream’s capital budget for the year ended December 31, 2019 and guidance. On January 8, 2019, Antero Midstream and AMGP also updated their monthly investor presentation. The updated investor presentation may be viewed on Antero Midstream’s website at www.anteromidstream.com, and a copy of the investor presentation is included as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated into this Item 7.01 by reference.

The information furnished in this Item 7.01 (including the exhibits) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, regardless of any general incorporation language in such filing, except as shall be expressly set forth by specific reference in such filing.

Item 8.01 Other Events.

To the extent required by law, the information in Item 7.01 of this Form 8-K is incorporated into this Item 8.01.

NO OFFER OR SOLICITATION

This Current Report, including the press release attached as an exhibit hereto, includes a discussion of a proposed business combination transaction (the “Transaction”) between Antero Midstream and AMGP. This communication is for informational purposes only and does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval, in any jurisdiction, pursuant to the Transaction or otherwise, nor shall there be any sale, issuance, exchange or transfer of the securities referred to in this document in any jurisdiction in contravention of applicable law. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

IMPORTANT ADDITIONAL INFORMATION

In connection with the Transaction, AMGP has filed with the U.S. Securities and Exchange Commission (“SEC”) a registration statement on Form S-4, which includes a joint proxy statement of Antero Midstream and AMGP and a prospectus of AMGP. The registration statement on Form S-4 has not been declared effective by the SEC, and the definitive joint proxy statement/prospectus has not yet been delivered to Antero Midstream unitholders or AMGP shareholders. INVESTORS AND SECURITY HOLDERS OF ANTERO MIDSTREAM AND AMGP ARE URGED TO READ THE REGISTRATION STATEMENT AND THE JOINT PROXY STATEMENT/PROSPECTUS REGARDING THE TRANSACTION AND ALL OTHER RELEVANT DOCUMENTS THAT ARE FILED OR WILL BE FILED WITH THE SEC, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE TRANSACTION AND RELATED MATTERS.

Investors and security holders will be able to obtain free copies of the registration statement and the joint proxy statement/prospectus (when available) and all other documents filed or that will be filed with the SEC by AMGP or Antero Midstream through the website maintained by the SEC at http://www.sec.gov. Copies of documents filed with the SEC by Antero Midstream will be made available free of charge on Antero Midstream’s website at http://investors.anteromidstream.com/investor-relations/AM, under the heading “SEC Filings,” or by directing a request to Investor Relations, Antero Midstream Partners LP, 1615 Wynkoop Street, Denver, Colorado 75219, Tel. No. (303) 357-7310. Copies of documents filed with the SEC by AMGP will be made available free of charge on AMGP’s website at http://investors.anteromidstreamgp.com/Investor-Relations/AMGP or by directing a request to Investor Relations, Antero Midstream GP LP, 1615 Wynkoop Street, Denver, Colorado 75219, Tel. No. (303) 357-7310.

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PARTICIPANTS IN THE SOLICITATION

AMGP, Antero Midstream, Antero Resources Corporation (“Antero Resources”) and the directors and executive officers of AMGP and Antero Midstream’s respective general partners and of Antero Resources may be deemed to be participants in the solicitation of proxies in respect to the Transaction.

Information regarding the directors and executive officers of Antero Midstream’s general partner is contained in Antero Midstream’s 2018 Annual Report on Form 10-K filed with the SEC on February 13, 2018, and certain of its Current Reports on Form 8-K. You can obtain a free copy of this document at the SEC’s website at http://www.sec.gov or by accessing Antero Midstream’s website at http://www.anteromidstream.com. Information regarding the executive officers and directors of AMGP’s general partner is contained in AMGP’s 2018 Annual Report on Form 10-K filed with the SEC on February 13, 2018 and certain of its Current Reports on Form 8-K. You can obtain a free copy of this document at the SEC’s website at www.sec.gov or by accessing AMGP’s website at http://www.anteromidstreamgp.com. Information regarding the executive officers and directors of Antero Resources is contained in Antero Resources’ 2018 Annual Report on Form 10-K filed with the SEC on February 13, 2018 and certain of its Current Reports on Form 8-K. You can obtain a free copy of this document at the SEC’s website at www.sec.gov or by accessing Antero Resources’ website at http://www.anteroresources.com.

Investors may obtain additional information regarding the interests of those persons and other persons who may be deemed participants in the Transaction by reading the joint proxy statement/prospectus regarding the Transaction when it becomes available. You may obtain free copies of this document as described above.

Item 9.01 Financial Statements and Exhibits

(d) Exhibits.

Exhibits |  | Description
99.1 |  | Antero Midstream Partners LP and Antero Midstream GP LP press release dated January 8, 2019.
99.2 |  | Antero Midstream Partners LP and Antero Midstream GP LP January 2019 Investor Presentation.

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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.

| ANTERO MIDSTREAM PARTNERS LP
| By: | Antero Midstream Partners GP LLC,
|  | its general partner
| By: | /s/ Glen C. Warren, Jr.
|  | Glen C. Warren, Jr.
|  | President and Secretary

Dated: January 9, 2019

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