DTM champion Martin Tomczyk leaves Audi

Tomczyk, 29, won three races on his way to the title this year, despite being demoted from the crack Abt Sportsline squad to an old-spec A4 run by the Phoenix Racing squad.

However, he now appears likely to join rival manufacturer BMW, which has been monitoring the German since January. Such a move would involve him linking up with Bruno Spengler, the man with whom he fought for this year's title.

"I won the championship for Audi after 11 years together. The entire Audi Sport team and in particular [head of Audi Sport] Dr Wolfgang Ullrich have always been behind me throughout the many years we spent together," Tomczyk said.

"I'm delighted that I could repay the trust by winning the 2011 championship title together with team Phoenix. Despite this joint success, and after careful consideration, I have now decided to accept a new challenge.

"I would once again like to thank everybody with whom I have worked together during my eleven years at Audi Sport and assure every single individual that these years were, in hindsight, something very special."

Ullrich praised the job done by Tomczyk during his time with the manufacturer, but said he was sorry to see him leaving.

"It goes without saying that we deeply regret that he decided, at this moment in time, to seek a new challenge after his most successful DTM season with Audi," said Ullrich.

"I can, however, completely understand that after eleven special years of highs and lows with Audi he would like to try something new - after all by winning the DTM title at the wheel of an Audi A4 DTM he has achieved exactly the goal for which he was worked so hard for many years.

"I'm personally delighted that Martin showed his many critics this year because I always believed in him. I can understand that to start he viewed the transfer to team Phoenix and a year-old car as demotion. But it gave, as I hoped, his career new impulses. I always enjoyed working together with Martin. He is a complete professional who I personally hold in high regard. I wish him all the best for the future."

Audi has confirmed that its 2012 line-up will be capped at seven new A5s, two of which will be driven by former champions Mattias Ekstrom and Timo Scheider.