Energy investment firm First Reserve Corp.  has agreed to acquire Ameriforge Group Inc. from Post Oak Companies LP, an affiliate of Houston-based private equity firm Tanglewood Investments Inc.

In partnership with Ameriforge’s management, the energy investment firm will acquire the company through First Reserve Fund XII. Financial terms were not disclosed. The transaction is subject to certain regulatory approvals and is expected to close in December.

Ameriforge is a vertically integrated manufacturer of engineered products, subassemblies and integrated systems for the oil and gas, midstream, downstream, power generation, aerospace, transportation and industrial markets.The executive management team will remain in place and will retain an equity interest in the company. In addition, the three founders and principals of Tanglewood will be continuing equity investors in Ameriforge.

Gean B. Stalcup, CEO of Ameriforge commented, “First Reserve’s investment represents a key milestone for our company. During our partnership with Tanglewood, we were able to transform Ameriforge from a single location flange forging company focused on the North Americanmarket to a fully-integrated, 29 facility international manufacturing enterprise which is providing a growing array of highly technical products and related services to the global energy, aerospace and transportation industries.”

Jeff Quake, managing director of First Reserve said, “We believe Ameriforge’s best-in-class manufacturing capability positions them well to participate in several of our core themes including international subsea development, the application of technology to extract unconventional resources and continued growth in recurring after-market related services.”

Michael L. Tiner, managing director of Tanglewood and current chairman of Ameriforge Group will remain with Ameriforge as a member of its board of directors.

Harris Williams & Co. is acting as the exclusive advisor to Ameriforge.