Henderson Group's £335m acquisition of Gartmore Group agreed Wednesday gives buyout firm Hellman & Friedman three times the cash it invested when it bought Gartmore almost five years ago, a person familiar with the situation told Dow Jones Newswires.

The San Francisco-based private equity firm bought the asset manager in May 2006 for just under £500m, backing management that included star fund manager Roger Guy, who subsequently joined the company board.