Ali Hariri, a former executive at Atheros Communications, pleaded guilty Wednesday to conspiracy and securities fraud in what federal prosecutors call the largest hedge fund inside trading case in history. It is one in a series of guilty pleas through which prosecutors are trying to draw a net around Raj Rajaratnam, founder and operator of the Galleon Hedge Fund.

Hariri admitted he tipped off a co-conspirator to Atheros' earnings report. The co-conspirator then bought more than half a million shares of Atheros before the public announcement sent the share price up by 6 percent. The co-conspirator made hundreds of thousands of dollars from the trades.

Hariri, 38, of San Francisco, faces a maximum of 25 years in prison at his June 10 sentencing.