• by Joe Mandese  @mp_joemandese, April 4, 2012

Cash-rich MDC Partners continues one of the most aggressive acquisitions campaigns Madison Avenue has seen since the early days of the Saatchis and WPP Group, announcing yet another significant stake this morning –- this one in one of America’s oldest and most fiercely independent agencies, Detroit-based Doner. MDC did not disclose terms of the deal, but described it as “significant minority interest, with the option to increase its stake to a majority interest at any time.”

The deal fits MDC’s model of acquiring significant and/or majority stakes in largely independent agencies and ensuring that their operating principals retain enough equity to keep their skin in the game.

In its most recent deals, MDC acquired majority stakes in two of the industry’s biggest independent media services agencies, R.J. Palmer and TargetCast TCM.

This morning’s announcement about Doner marks an end to one of the longest runs of a large independent agency. Founded in 1937, the Detroit shop claims a staff of 600 and billings of more than $1 billion with offices in Cleveland, London and Newport Beach.

MDC said its connection developed after Doner recruited Rob Strasberg, former creative chief at MDC’s Crispin Porter + Bogusky, as its co-CEO.

Doner, which has a strong creative reputation, has focused on expanding its capabilities over the past decade to include a strong media planning and buying practice, and sophisticated production facilities, advanced digital expertise and strong analytics capabilities. The shop has a roster of clients including ADT, AutoTrader.com, Avery Dennison, Choice Hotels International, Chrysler Group LLC, The Coca-Cola Company, The Coleman Company, Cox Communications, DuPont, Harman, Serta Sherwin-Williams, Shell Lubricants and The UPS Store.