Los Angeles--Blagman Media Inc., a direct marketing and advertising agency, Friday signed a definitive agreement to acquire ad agency Century Media Inc. Terms were not disclosed. The combined entity will be called Blagman/Century Media. Combined billings for 2001 were $50 million. Both staffs will be absorbed under the new entity, which will employ 40 people. The companies said the new entity will reach $65 million in billings this year and expects to top $100 million in 2003.