Late last year, a case against former SAC trader Mathew Martoma—who has so far pleaded not guilty to insider trading charges—drew the firm's founder, Steve Cohen, into the mix based on an allegation that he authorized a sale of two pharmaceutical holdings motivated by insider knowledge.
(Read More: SAC Capital's Martoma Pleads Not Guilty)
Cohen has insisted he behaved properly, and SAC informed investigators that it had opposing positions in the two pharmaceutical stocks that offset any economic gains from the Martoma sales.
Nonetheless, worried investors pulled almost $1.7 billion from the $15 billion hedge fund in January, and SAC now faces another possible exodus on May 15, the next point at which capital can be redeemed.
(Read More: SAC Loses $1.68 Billion From Investors)
Some major outside investors—including Blackstone Group's alternative asset unit, which, after a small redemption in February, still has at least $410 million invested in SAC—have indicated that they are considering withdrawals.
(Read More: Blackstone Keeps Most of Its Money With SAC)
In February, SAC modified its longstanding redemption policy, under which investors had to wait four quarters to receive all their money back, as a way to appease Blackstone, among others, said people familiar with that situation. It's now relaxing the modified policy yet again.
"We are offering our investors additional time to make their decisions as we are hopeful that the next few months will bring greater clarity surrounding the resolution of pending regulatory matters," SAC President Tom Conheeney said in an emailed statement.
—By CNBC's Kate Kelly; Follow her on Twitter: