Federal Bureau of Investigation agents raided the offices of three hedge funds as part of a high-profile insider-trading investigation

The offices of Diamondback Capital Management LLC and Level Global Investors LP were raided. Both hedge funds are run by former managers of Steven Cohen's SAC Capital Advisors.

The third firm raided is Loch Capital Management LLC, based in Boston, people familiar with the matter say. Leonard Pierce, a lawyer for Loch Capital, declined to immediately comment.

'The FBI is executing court-authorized search warrants in an ongoing investigation,' said Richard Kolko, an FBI spokesman, who declined to comment further.

Loch had $750 million in assets as of the start of this year, according to SEC filings. The firm, run by brothers Timothy and Todd McSweeney, didn't immediately return a message seeking comment. Leonard Pierce, a lawyer for Loch Capital, declined to immediately comment.

FBI agents raided the offices of three hedge funds -- Diamondback Capital Management, Level Global Investors and Loch Capital Management -- as part of a high-profile insider-trading investigation. Dennis Berman has details.
.The McSweeney brothers are acquaintances with Steven Fortuna, a hedge-fund manager who pleaded guilty in the Galleon case and agreed to cooperate in that ongoing investigation.

Level Global Investors LP is a Greenwich, Conn., hedge-fund firm run by David Ganek, a former SAC Capital trader and art collector. He started Level Global in 2003 and earlier this year reported managing about $4 billion in assets.

Diamondback Capital Management LLC is based in Stamford, Conn., and was started in 2005. It oversees more than $5 billion in assets, according to SEC filings.

The moves by the FBI follow an article by The Wall Street Journal describing an insider-trading investigation that is expected to encompass consultants, investment bankers, hedge-fund and mutual-fund traders. The investigation is said by people close to the situation to eclipse in size and magnitude past insider-trading probes.

Messages left with Richard Schimel, Diamondback's co-chief investment officer, and Diamondback's general counsel, Joel Harary, on their office phones weren't immediately returned.