Riverstone Holdings LLC announced last month that a consortium led by Riverstone has signed a definitive agreement to acquire Dresser Inc. Riverstone is joined by First Reserve and Lehman Brothers Co-Investment Partners in the investor group. First Reserve previously acquired Dresser in 2001 in partnership with Odyssey Investment Partners and will invest in the current transaction through its recently formed First Reserve Fund XI, L.P.

Riverstone will invest through its Carlyle/Riverstone Global Energy and Power Fund III, L.P. The terms of the transaction were not disclosed.

Dresser, based in Dallas, is a leading manufacturer and marketer of valves, actuators, meters, switches, regulators, piping products and other engineered products for the energy industry. The company has manufacturing and customer service facilities in 20 countries and a sales presence in over 100 countries.

Riverstone Holdings LLC and The Carlyle Group are the co-general partners of Carlyle/Riverstone Global Energy and Power Funds. Riverstone, a New York-based energy and power focused private equity firm founded in 2000, has $8 billion under management. The Carlyle Group is a global private equity firm with $51.8 billion under management. Since 1987, the firm has invested $24 billion of equity in 576 transactions.

First Reserve is the oldest and largest private equity firm specializing in the energy industry. Since 1992, First Reserve has raised over $12.7 billion for its buyout-focused funds.

Lehman Brothers Co-Investment Partners is a $1.6 billion fund that invests alongside premier private equity funds globally. Founded in 1850, Lehman Brothers is a leading investment bank.