MPLX LP filings document the disclosure record of a Delaware master limited partnership with common units representing limited partnership interests listed on the New York Stock Exchange. Its reports include 8-K disclosures for operating results and financial condition, exhibits containing earnings releases, and annual reporting on the partnership's midstream energy infrastructure and logistics business.
The filing record also covers capital-structure and financing matters, including revolving credit agreements, underwriting agreements, supplemental indentures, and debt-securities exhibits filed under registration statements. Governance disclosures address MPLX GP LLC as general partner, board and officer changes, compensatory arrangements, shareholder voting matters, material-event reporting, and risk disclosure tied to the partnership's operations and securities.
Insider acquisition recorded: On 08/25/2025 Ray N. Walker Jr., a director of MPLX GP LLC (the general partner of MPLX LP), was reported acquiring 1,677.632 common units of MPLX at a stated price of $0. Following the transaction, he beneficially owns 1,677.632 units. The filing is signed by an attorney-in-fact on behalf of Mr. Walker.
MPLX LP director files initial ownership report showing no units held. Ray N. Walker Jr., a director of MPLX GP LLC, the general partner that manages MPLX LP, filed an initial insider ownership statement as of August 25, 2025. The filing reports beneficial ownership of 0 common units of MPLX LP, held directly. This is a routine regulatory disclosure of insider holdings and does not describe any purchase or sale transaction.
MPLX LP reported that, on August 25, 2025, the board of managers of MPC Investment LLC, the sole member of MPLX GP LLC, increased the size of the board of directors of the general partner to eleven members and elected Ray N. Walker, Jr. as a director, effective the same day. He is expected to serve on the audit committee and the conflicts committee, which oversee financial reporting and related-party or conflict‑sensitive matters.
As a non‑management director, Mr. Walker will receive compensation in the same manner as the partnership’s other non‑management directors, under terms previously described in MPLX LP’s Annual Report on Form 10‑K for the year ended December 31, 2024.
John P. Surma, reported as a director of MPLX GP LLC (the general partner of MPLX LP), executed a transaction on 08/15/2025 acquiring 1,475.301 common units (limited partner interests). The form reports a price of $0 for the transaction and shows 86,095.058 common units beneficially owned following the reported transaction. The filing was signed by an attorney-in-fact, Molly R. Benson, on 08/19/2025.
Director J. Michael Stice reported an acquisition of MPLX common units. On 08/15/2025 he acquired 962.494 common units at a reported price of $0, increasing his total beneficial ownership to 51,275.827 common units. The filing shows 700 units held indirectly by The Mike Stice Trust. The reporting person is a director of MPLX GP LLC, the issuer's general partner.
Frank M. Semple, a director of MPLX GP LLC, reported a transaction in MPLX common units on 08/15/2025. The filing shows an acquisition of 1,050.574 common units at a reported price of $0, and indicates 55,968.214 common units beneficially owned following the transaction as direct holdings. Additional indirect holdings are reported: 333,337 units through Frank M Semple Revocable Trust, 111,180 through Robin Y Semple 2012 Dynasty Trust, and 48,777 through EK Holdings LLC. The form is signed by an attorney-in-fact on behalf of Mr. Semple.
Garry L. Peiffer, a director of MPLX GP LLC (the general partner of MPLX LP), reported an acquisition of 1,157.128 common units of MPLX on 08/15/2025. The reported transaction lists a price of $0. After the transaction, the filing shows 61,644.675 common units beneficially owned directly and 68,497 beneficially owned indirectly by the Garry L. Peiffer Revocable Trust. The Form 4 was signed by an attorney-in-fact on 08/19/2025.
Insider transaction reported for MPLX LP (MPLX). Christopher A. Helms, listed as a director of MPLX GP LLC (the issuer's general partner), reported acquiring 1,259.684 common units on 08/15/2025 at a reported price of $0, bringing his beneficial ownership to 78,108.263 common units. The form was signed by an attorney-in-fact on 08/19/2025.
The filing reports that Christine S. Breves, a director of MPLX GP LLC (the general partner of MPLX LP), acquired 213.782 common units of MPLX on 08/15/2025 at a reported price of $0. After the transaction she beneficially owned 11,388.941 common units. The form indicates Breves files as a reporting person and was signed on behalf of Breves by Molly R. Benson, Attorney-in-Fact, on 08/19/2025.
MPLX LP filed an 8-K reporting that it has added several exhibits to its Form S-3 registration statement. The filing includes an underwriting agreement naming J.P. Morgan Securities LLC, Goldman Sachs & Co. LLC, BofA Securities, Inc., Mizuho Securities USA LLC, TD Securities (USA) LLC and Wells Fargo Securities, LLC as representatives of the underwriters; four supplemental indentures (Thirty-Second through Thirty-Fifth) with The Bank of New York Mellon Trust Company, N.A. as trustee that include forms of note; and a legal opinion and consent from Jones Day. These exhibits establish the legal and underwriting framework to issue multiple series of notes, but the filing does not disclose offering sizes, interest rates, maturities or other financial terms.