The account move is effective March 1. Billings weren't revealed.
Rick Balsiger, Isuzu's vice president of marketing and product planning, said the automaker, 49% owned by GM, wants to take advantage of marketing efficiences that the relationship offers.
MPG, formerly SFM Media, had the account from 1982 to 1987 and from 1991 to the present.
Isuzu's annual measured media spending has seesawed recently. In 2000, the marketer spent $38 million vs. $58 million in the first nine months of 2001, according to Taylor Nelson Sofres' CMR.
Isuzu isn't profitable. Its vehicle sales slipped to 82,380 units last year from 98,066 the prior year, according to Advertising Age sibling Automotive News.
Omnicom Group's Goodby, Silverstein & Partners, San Francisco, will keep the creative account even in the wake of its win Thursday of GM's estimated $300 million national and regional Saturn Corp. account.