By Pamela Barbaglia and Echo Wang LONDON/NEW YORK - A sale of Manchester United Plc could provide the soccer club's controlling shareholders, the Glazer family, a lucrative exit from an investment that has languished over the past decade and drawn the ire of millions of soccer fans. Deals for European football clubs this year, beginning with the sanctions-driven sale of Chelsea Football Club by Russian oligarch Roman Abramovich in May, have fetched top dollar. It's these rich valuations that have motivated the Glazers to formally put Manchester United up for sale, according to two people familiar with the matter. The family, which made its fortune in real estate, retail and healthcare and also owns the Tampa Bay Buccaneers, bought the team for 790 million pounds ($939.07 million) in 2005. A sale at valuations commensurate with deals like Chelsea would yield a profit of several billion dollars, the sources said.