Joseph C. Lewis, who became a billionaire trading currencies, has taken a 7 percent stake in Bear Stearns Cos Inc (BSC), snapping up about $860 million worth of the investment bank's stock over the past two months.

Bear Stearns' shares rose 3 percent to $108.57 in early trading on the New York Stock Exchange.

Lewis disclosed the stake Monday in a filing with the U.S. Securities and Exchange Commission. The purchases would make Lewis one of Bear Stearns' biggest shareholders, if not the largest.

At the end of June, Putnam Investment Management was Bear's largest institutional shareholder with 7.03 million, or 6 percent, of Bear's outstanding shares. Lewis owns 8.1 million shares of Bear Stearns, according to the SEC filing.

Bear Stearns' shares are down 35 percent this year, hammered by the collapse of two hedge funds and its heavy reliance on mortgage-related revenue amid a meltdown in the subprime lending industry.

Born in London, Lewis operates from the Bahamas and Florida. His investments include English Premier League soccer club Tottenham Hotspur. His investment vehicle, Tavistock Group, holds interests in more than 170 companies in 15 countries.

He was not immediately available for comment.

Lewis-controlled entities named Aquarian, Cambria, Darcin, Mandarin and Nivon bought large blocks of Bear Stearns shares in August and September, the SEC filing shows. The last reported purchase was a block of 400,000 shares on Sept. 4.