?Greenwich, Conn.-based private-equity firm First Reserve Corp. has closed its most recent global buyout fund, First Reserve Fund XII LP, with $9 billion in commitments. Fund XII will provide privately negotiated equity and equity-related investments in a diversified portfolio of companies in the global energy industry. The fund initially closed in mid-July 2008 and was raised in less than a year, a compressed timetable for funds this size.

William Macaulay, First Reserve chief executive, says, “Fund XII provides us ample equity during what is expected to be an attractive investment environment in the coming years. It gives us the resources to continue to secure strategic market positions, often with industry partners, and gives us access to high-quality deal flow. Energy remains a large, dynamic and complex industry where change creates new, attractive investment opportunities. Our experience of investing successfully throughout varying economic cycles is an advantage in the current environment and will provide long-term opportunities for our valued Fund XII investors.”

First Reserve previously raised $7.8 billion in First Reserve Fund XI LP in 2006; its acquisitions included Brand Energy & Infrastructure Services from J.P. Morgan Partners LLC in February 2008.

Fund XII is believed to be the largest private-equity fund ever formed to make investments in the energy industry, according to law firm Simpson Thacher, which represented First Reserve.

Recently announced investments include an agreement between portfolio company Cobalt?International Energy and Total E&P USA concerning interest on 214 joint Gulf of Mexico deepwater leases and an agreement with Siemens Financial Services for an investment in the Longview Power project in West Virginia.