Washington, D.C. ? The Bush administration’s cybersecurity chief, who worked under an unusual agreement with a private university that does extensive business with the office he manages, is leaving his job.

Donald “Andy” Purdy Jr. will step down as acting director of the National Cyber Security Division, part of the Department of Homeland Security. A government spokesman, Jarrod Agen, declined to comment on Purdy’s plans, but colleagues circulated an invitation to his farewell party next week.

Purdy worked at Homeland Security under a two-year contract with Carnegie Mellon University that expires Oct. 3. Under the contract, the government paid Purdy $245,481 in salary and benefits each year, not including travel reimbursements; Carnegie Mellon paid him an additional $43,320 a year.