USA Compression Partners, a natural gas compression services provider and portfolio company of Riverstone Holdings and The Carlyle Group, has begun trading on the NYSE under the symbol USAC. The first IPO of 2013, USA Compression sold 11 million shares at $18 per share, and will use the proceeds to repay indebtedness. Riverstone and Carlyle acquired the company in 2010 through the pair's Global Energy and Power Funds, a group of energy-focused private equity funds.