Reitzle exit latest setback for Jaguar.

One of Jaguar Racing's biggest backers has quit the Ford-owned Premier Automotive Group, which oversees the running of the Formula One team.

Wolfgang Reitzle, the former BMW executive, confirmed his intention return to a higher management post in his native Germany overnight, and will be replaced by the current president of Mazda, Mark Fields.

Reitzle is known to be pro-motorsport, and has helped maintain Jaguar's racing project in the face of falling profits at the Blue Oval. He also represented Ford on the board of the recently-formed GPWC - the group set up to run the auto giants' rival race series from 2008.

Reitzle leaves Niki Lauda behind at PAG, and the Austrian could now face a tough battle to keep Jaguar in Formula One. With money becoming tight back at the parent company - which recently reported an $800m first quarter loss - Ford will demand more than a couple of fortunate points in the season-opening race in Australia to justify funding future seasons for the team.

Reitzle is thought to be joining German engineering firm Linde AG as CEO.