AdAge broke the story just before the weekend that General Motors was putting up its $2.8 billion media account into review. GM's budget is the second largest marketing budget in the world, and the automaker is also one of the biggest online spenders. Incumbents Mediaworks (national) and LCI (regional) were both invited to defend the accounts. Mediaworks has been fending off inroads made by arch competitor Starcom for the last few years. Starcom took the outdoor media account last year, and its Planworks sibling has been handling media planning for GM since 2000.