* Picks up minority stake in Doner for undisclosed sum

* Raises 2012 revenue forecast by $50 mln

* Raises 2012 EBITDA view by $8 mln

* Shares up 5 percent

April 4 (Reuters) - Canada's MDC Partners Inc raised its 2012 revenue outlook by $50 million, as the advertising and marketing company won new clients and acquired a stake in a Detroit-based agency.

The company picked up a "significant" interest in Doner, which counts Chrysler Group LLC, Coca-Cola Co, Coleman Co and AutoTrader.com as it clients.

"We have a substantial minority (in Doner) and ... will ultimately, convert our convertible preferred, and go to majority," Chief Executive Miles Nadal said in a conference call.

MDC Partners did not disclose the financial details of the deal but said it would not spend more than $10-$15 million on acquisitions this year.

MDC owns nearly 50 agencies located in the United States, Canada, Sweden and the United Kingdom. It raised its 2012 revenue outlook to between $1.05 billion and $1.08 billion from the earlier estimate of between $1 billion and $1.03 billion.

"Our net new business wins were in excess of $40 million in the first quarter, versus a modest $8 million in the first quarter of last year," Nadal said.

MDC also raised the estimate for its earnings before interest, taxes, depreciation, and amortization (EBITDA) by $8 million to between $110 million and $115 million.

"We have more in the pipeline, and we expect a material ramp up in profitability in Q2," the CEO said.

MDC shares were trading up 5 percent at C$11 on Wednesday on the Toronto Stock Exchange.

• A Permanent Economic Emergency