Hedge fund titan Steven A. Cohen is giving investors more time to withdraw their money from SAC Capital Advisor’s funds, as his $15-billion firm faces continued federal scrutiny in an insider trading investigation.

With about three weeks to go before investors in SAC Capital Advisors need to decide on whether they are pulling their money out, Cohen is offering them a quicker way to access their cash in a bid to convince them to stick with him.

“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,” said SAC Capital President Tom Conheeney.

Investors will now be able to get back 50 percent of their money in each of the last two quarters of the year, the firm told investors. This marks the second time in about two months that SAC has adjusted its liquidity conditions.

Initially, the firm would pay back withdrawals spread out over four quarters. Then the firm hastened the payouts to one third of investors’ fund stakes per quarter and now it will be half per quarter.

Cohen and his senior executives have been speaking to investors and one source familiar with the discussions says clients have reacted positively. The source said that the firm felt it could offer these more generous liquidity conditions without jeopardizing the funds.

Outsiders’ money accounts for only about $6 billion of the firm’s money under management, but Cohen appears to be trying to pacify jittery clients who said in February that they wanted to pull out $1.7 billion at the end of the first quarter.

Since that deadline, the firm agreed to pay $616 million to settle an insider trading case with the Securities and Exchange Commission. A few weeks after that, Michael Steinberg, one of Cohen’s top portfolio managers, was arrested and charged with insider trading.

One of SAC’s most important clients is Blackstone Group , which has some $550 million with Cohen and was instrumental in negotiating the better conditions in February. At the time, Blackstone was staying put.

(CM Editor’s Note: In the property/casualty insurance industry, Cohen is a founding investor of Bermuda-based S.A.C. Re Holdings.)