MPLX LP filed a Form 8-K with the U.S. Securities and Exchange Commission on August 24, 2026, disclosing the execution of three supplemental indentures and an underwriting agreement in connection with its Registration Statement on Form S-3 (Registration No. 333-295600).

Key Highlights

  • Underwriting Agreement: Dated August 10, 2026, executed among MPLX LP, MPLX GP LLC, and representatives TD Securities (USA) LLC, Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, SMBC Nikko Securities America, Inc., and Wells Fargo Securities, LLC.
  • Thirty-Eighth Supplemental Indenture: Dated August 24, 2026, between MPLX LP and The Bank of New York Mellon Trust Company, N.A., as Trustee, including a Form of Note.
  • Thirty-Ninth Supplemental Indenture: Dated August 24, 2026, between MPLX LP and The Bank of New York Mellon Trust Company, N.A., as Trustee, including a Form of Note.
  • Fortieth Supplemental Indenture: Dated August 24, 2026, between MPLX LP and The Bank of New York Mellon Trust Company, N.A., as Trustee, including a Form of Note.
  • Legal Opinion: An opinion of Jones Day was filed as an exhibit, with Jones Day's consent included within that exhibit.

MPLX LP Executes Three Supplemental Indentures and Underwriting Agreement

According to the filing, MPLX LP (NYSE:MPLX), a Delaware limited partnership headquartered at 200 E. Hardin Street, Findlay, Ohio, submitted the current report under Item 8.01 (Other Events) to file exhibits related to its Registration Statement on Form S-3 (Registration No. 333-295600). The filing was signed by Molly R. Benson, Chief Legal Officer and Corporate Secretary of MPLX GP LLC, the general partner of MPLX LP.

The filing disclosed that an Underwriting Agreement was dated as of August 10, 2026, listing TD Securities (USA) LLC, Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, SMBC Nikko Securities America, Inc., and Wells Fargo Securities, LLC as representatives of the several underwriters named therein. The three supplemental indentures, each dated August 24, 2026, were entered into between the Issuer and The Bank of New York Mellon Trust Company, N.A., acting as Trustee, and each includes a Form of Note.

The filing identified the documents submitted as exhibits under Item 9.01(d), comprising the Underwriting Agreement (Exhibit 1.1), the Thirty-Eighth, Thirty-Ninth, and Fortieth Supplemental Indentures (Exhibits 4.1, 4.2, and 4.3, respectively), and the Opinion of Jones Day (Exhibit 5.1), along with Jones Day's consent (Exhibit 23.1) and a Cover Page Interactive Data File (Exhibit 104).

What Was Disclosed

MPLX LP disclosed the filing of exhibits to its Form S-3 registration statement, including an underwriting agreement dated August 10, 2026, three supplemental indentures each dated August 24, 2026, and a legal opinion from Jones Day.