Davidson Kempner Capital Management told clients that it will no longer accept new capital for its flagship multistrategy fund as of April 1 and from now on will only replace redemptions, according to investors. That fund, the Davidson Kempner Institutional Partners Fund, returned 8.75% in 2010 and was up about 3.25% in the first quarter. It now manages $5.7 billion. The firm increased assets to $16.2 billion as of the end of February and was one of the biggest winners in AR’s Billion Dollar Club, having raised more than $4 billion in 2010 alone. With these gains, Davidson Kempner has surpassed the $14.6 billion midyear peak it achieved in 2008 before the financial crisis. A spokesman for Davidson Kempner declined to comment.