Oct. 22 (Bloomberg) -- Sri Lankan billionaire Raj Rajaratnam today returned to Manhattan federal court, where he faces charges of trading on inside information, to post his Manhattan apartment as security for a $100 million bail bond.

Rajaratnam was among six people charged on Oct. 16 in a $20 million insider trading scheme that federal prosecutors called the biggest ever involving hedge funds. He was freed by a magistrate judge on a $100 million bond, of which $20 million had to be guaranteed. He and his lawyer today filed a document offering his apartment at 60 Sutton Place South in Manhattan as the guarantee.

Rajaratnam and his lawyer, James Walden, didn’t comment as they left the courthouse in lower Manhattan for a waiting SUV. Today was the deadline for him to post the guarantee. Rajaratnam, the founder of the Galleon Group hedge fund, has denied wrongdoing.

Prosecutors said the case is the first in which wiretaps were used to target insider trading, signaling the government will now use the same tools against Wall Street that it employs in organized crime and drug cases.

The case is U.S. v. Rajaratnam, 09-02306, U.S. District Court, Southern District of New York (Manhattan).

To contact the reporters on this story: David Glovin in New York federal court at dglovin@bloomberg.net.

Last Updated: October 22, 2009 13:37 EDT