Open Solutions, a portfolio company of The Carlyle Group and Providence Equity Partners, has been acquired by Fiserv (NASDAQ: FISV) for $55 million. Fiserv also assumed approximately $960 million of debt with the purchase. Based in Glastonbury, CT, Open Solutions provides account processing technology to banks, thrifts and credit unions. The company serves more than 3,300 clients worldwide, including more than 800 account processing clients. Carlyle and Providence took the company private in January 2007.