Martin A. Siegel’s sentencing was rescheduled.

Siegel, a key cooperative witness in the government’s probe into Wall Street corruption, will be sentenced July 9 on charges of illegal stock trading and tax evasion, U.S. Attorney’s office spokeswoman Deborah Corley said. It was the second postponement for the former investment banker, who pleaded guilty in February to the criminal charges stemming from the Wall Street insider trading scandal. Siegel was once the top merger specialist for the investment firms Drexel Burnham Lambert and Kidder, Peabody & Co. He faces a maximum 10 years in prison and $260,000 in fines for the two felony counts.