The Swiss manufacturer of the AIDS treatment drug Serostim has agreed to pay more than $700 million to settle allegations that it offered kickbacks to doctors to write prescriptions to boost sagging sales, government and company officials said Monday.

The Justice Department settlement with Serono Laboratories of Switzerland was to be announced later Monday by Attorney General Alberto Gonzales. The officials spoke on condition of anonymity because they were not authorized to discuss the case publicly in advance of the announcement.