PARIS, May 21 (Reuters) - A bitter battle over the future of Atos Origin is set for a climax at Thursday's annual meeting when shareholders will vote on demands from two activist funds to oust its supervisory chairman and overhaul its board.

The funds, Pardus Capital Management and Centaurus Capital, who have built a 23 percent stake in the French IT services group, are pushing for a change in strategy to speed up its recovery and generate higher returns, and possibly a sale.