MPLX Elects Maryann T. Mannen as Chairman of the Board

Rhea-AI Summary

MPLX (NYSE:MPLX) announced that its general partner board elected Maryann T. Mannen as chairman of the board, effective Jan. 1, 2026.

Mannen will add the chairman role to her current duties as president and chief executive officer. She succeeds Michael J. Hennigan, who will retire as executive chairman and as a board member of the general partner, also effective Jan. 1, 2026. Chris Helms will continue as independent lead director.

The announcement also notes Mannen will succeed Hennigan as chairman of MPC and continue as MPC president and CEO, effective Jan. 1, 2026.

Positive

• Clear succession plan with effective date Jan. 1, 2026
• Internal promotion: CEO Maryann Mannen elevated to chairman
• Independent lead director Chris Helms remains in role

Negative

• Chairman and CEO roles consolidated under Maryann Mannen
• Retirement of long-serving chairman Michael J. Hennigan

FINDLAY, Ohio, Nov. 4, 2025 /PRNewswire/ -- MPLX LP (NYSE: MPLX) today announced that the board of directors of the general partner of MPLX has elected Maryann T. Mannen, president and chief executive officer and member of the board, as chairman of the board, effective Jan. 1, 2026. Mannen will assume the role of chairman of the board in addition to her current responsibilities. Mannen will succeed Michael J. Hennigan, who has elected to retire as executive chairman and as a member of the board of directors of the general partner of MPLX, also effective Jan. 1, 2026. Chris Helms will continue to serve as the independent lead director of the board.

"On behalf of the entire board of directors, we extend our congratulations to Maryann as our new leader and our gratitude to Mike for his dedication to the partnership," said Mr. Helms.

Mr. Hennigan has led the general partner of MPLX as chairman of the board of directors since April 2020, as CEO from November 2019 to August 2024, and as President from June 2017 to August 2024. Ms. Mannen has served as CEO since August 2024 and as a member of the board of directors since February 2021.

Also announced today and effective Jan. 1, 2026, Mr. Hennigan will retire as executive chairman of MPC, with Ms. Mannen to succeed him as chairman and continuing to lead MPC as its president and CEO.

About MPLX LP
MPLX is a diversified, large-cap master limited partnership that owns and operates midstream energy infrastructure and logistics assets and provides fuels distribution services. MPLX's assets include a network of crude oil and refined product pipelines; an inland marine business; light-product terminals; storage caverns; refinery tanks, docks, loading racks, and associated piping; and crude and light-product marine terminals. The company also owns crude oil and natural gas gathering systems and pipelines as well as natural gas and NGL processing and fractionation facilities in key U.S. supply basins. More information is available at www.MPLX.com.

Investor Relations Contact: (419) 421-2071
Kristina Kazarian, Vice President Finance and Investor Relations
Brian Worthington, Senior Director, Investor Relations
Isaac Feeney, Director, Investor Relations
Evan Heminger, Analyst, Investor Relations

Media Contact: (419) 421-3577
Jamal Kheiry, Communications Manager

View original content:https://www.prnewswire.com/news-releases/mplx-elects-maryann-t-mannen-as-chairman-of-the-board-302603327.html

SOURCE MPLX LP

FAQ

When will Maryann T. Mannen become chairman of MPLX (MPLX)?

Maryann T. Mannen will assume the chairman role effective Jan. 1, 2026.

Will Maryann Mannen keep her CEO role after becoming MPLX chairman (MPLX)?

Yes. Mannen will add the chairman title while continuing as president and chief executive officer.

Who is retiring from the MPLX general partner board and when?

Michael J. Hennigan will retire as executive chairman and as a board member effective Jan. 1, 2026.

Who will serve as MPLX independent lead director after the change (MPLX)?

Chris Helms will continue to serve as the independent lead director of the board.

Does the announcement affect MPC leadership and when?

Yes. Mannen will succeed Hennigan as chairman of MPC and continue as MPC president and CEO effective Jan. 1, 2026.