FRANKFURT - Manfred Wennemer resigned from his post as one of the five board members of the Opel Trust on Saturday in protest against the constant interference by politicians in Germany surrounding planned sale of Opel.

While potentially embarrassing to Berlin, the move is essentially symbolic since the trust no longer has to approve a deal now that Opel parent General Motors GM.UL changed its mind this week and decided against a disposal after roughly half a year of protracted negotiations that were complicated by government involvement.

Appointed to the board to represent the interests of a German federal government, Wennemer broke ranks and voted against a deal with Magna heavily backed by Chancellor Angela Merkel just days before her conservative CDU party was running re-election.

Wennemer, a respected manager and former chief executive of German parts supplier Continental, accepted the job as trustee in order to find a sensible solution for Opel on the basis of economic criteria, according to a statement from the Opel Trust.

He had argued at the time Opel was too small to survive on its own, even if GM were to retain 35 percent in order to achieve scale effects. This would put the 4.5 billion euros ($6.7 billion) in total taxpayer aid at significant risk.

Dirk Pfeil, appointed by the four German states home to Opel plants, was summarily axed as a board member of the Trust after he openly supported a GM's shock reversal to terminate the sale just days ahead of the signing that infuriated Berlin along with the local governments.

DETROIT BAILOUT

Pfeil argued on Friday that Magna had no competence in building cars, although Magna in fact has a assembly business in Graz where it builds the Aston Martin Rapide and BMW X3.

The board member publically favored GM's preferred bidder RHJ, a hitherto largely unknown financial investor that owns a few assets that supply forged metal parts for the auto industry. GM had indicated it would be open to buying a restructured Opel back from RHJ at a later date.

Speaking to weekly magazine WirtschaftsWoche, Pfeil called on Germany and its organized labor to offer the same state aid and wage concessions to GM that were extended to Magna.

(Reporting by Christiaan Hetzner; editing by Chris Pizzey)