Avista Capital Partners is an American private equity firm focused on growth capital and leveraged buyout investments in middle-market companies in the energy, healthcare and media sectors. The firm, which is based in New York City, was founded in 2005 when a team of professionals, led by Thompson Dean and Steven Webster, completed a spinoff from Credit Suisse's private equity arm DLJ Merchant Banking Partners to form a new private equity firm. Dean had previously been the co-head of DLJMB.