A high-profile defendant in the government’s wide-ranging insider trading case is expected to plead guilty and provide damning information about the alleged ringleaders, Raj Rajaratnam and Danielle Chiesi.

Prosecutors told a federal judge yesterday that Mark Kurland, co-founder of a former Bear Stearns hedge fund, plans to waive indictment today in the $50 million case.

Kurland, 60, could dish on Chiesi, a former employee of his hedge fund, New Castle. Chiesi is at the center of the insider trading case, along with Rajaratnam, the billionaire founder of the Galleon Group hedge fund. Both have been indicted and have pleaded not guilty.