A former Morgan Stanley client service representative pleaded guilty yesterday to possessing a stolen list of the firm’s prime brokerage clients, among other proprietary information.

In addition to the list of hedge fund clients, Ronald Peteka admitted he received via e-mail formulas used to calculate rates paid by those clients, sending the stolen information to his Long Island, N.Y., home. Another former Morgan Stanley employee, Ira Chilowitz, pleaded guilty last year to stealing the data, which he said he and Peteka planned to use to generate business for a consulting firm.

“I made a very huge mistake,” Peteka said at the hearing at Manhattan federal court. He faces as much as 10 years in prison and a $250,000 fine.