The embattled hedge fund SAC Capital Advisors is bracing itself for another round of withdrawal requests from investors after disclosing that it would no longer fully cooperate with the government’s scrutiny of its trading practices, the New York Times DealBook blog reported today. SAC’s investors have two weeks to decide whether to withdraw money from the $15 billion hedge fund, which is owned by Steven A. Cohen. Earlier this year, SAC investors asked to redeem $1.7 billion, and the firm is scrambling to stanch the outflow of more funds as fears rise that the insider trading investigations could further damage Cohen and his firm.