(Bloomberg News) Former SAC Capital Advisors LP portfolio manager Mathew Martoma was charged in what U.S. prosecutors called "the most lucrative insider-trading scheme ever," netting as much as $276 million while at the hedge fund.

Prosecutors in the office of U.S. Attorney Preet Bharara in Manhattan today unsealed a complaint charging Martoma with trading on illicit tips about Alzheimer's disease drug-trial results from 2006 to 2008.

Martoma is accused of arranging trades in shares of Wyeth LLC and Elan Corp., making $220 million in profits and avoiding $56 million in losses for an unnamed hedge fund. Martoma is charged with one count of conspiracy and two counts of securities.

Mathew Martoma, 38, of Boca Raton, Florida, worked for CR Intrinsic Investors in Stamford, Connecticut, a unit of SAC Capital, according to a civil complaint lawsuit filed against him by the U.S. Securities and Exchange Commission. Martoma allegedly engaged in the misconduct while at CR Intrinsic, according to the SEC complaint.

The SEC sued Martoma, CR Intrinsic and Dr. Sidney Gilman, the neurologist who allegedly supplied the tips. A phone call to Gilman's home in Ann Arbor, Michigan, wasn't immediately returned.

"This is an insider trading case where affiliated investment advisors and their hedge funds made over $276 million in illegal profits or avoided losses in July 2008 by trading ahead of a negative public announcement involving the clinical trial results for an Alzheimer's drug being jointly developed by Elan Corp. Plc and Wyeth," according to the SEC complaint.

Prosecutors said Martoma, who worked as a portfolio manager specializing in health care, was paid a bonus of $9.4 million in January 2009, based largely on the hedge fund's profits from the Wyeth and Elan trades.

Jonathan Gasthalter, a spokesman for Stamford-based SAC, had no immediate comment.

The case is U.S. v. Martoma, 12-MAG-2985, U.S. District Court, Southern District of New York (Manhattan).