BMW Motorsport is considering quitting the World Touring Car Championship, following on-going disputes over the technical regulations.
The championship has been plagued by the continued wrangling over the equalisation of BMW's 320si and the turbo-diesel SEAT Leon TDi hatchbacks, and BMW motorsport boss Mario Theissen has admitted that BMW's patience with the series is wearing thin.
"In my opinion the situation is not sustainable and we are presently examining our WTCC commitment very critically," he told the press in Monaco.
"We have always been in touring car racing in some form or other, and we will continue in that way. But we have a very broad base of customers so it doesn't necessarily have to be a works engagement."
BMW ended last season frustrated that its car was unable to compete with the turbo-diesel-powered SEAT Leons. SEAT had its boost pressure restricted to 2.5 bar prior to the beginning of this season, but BMW was still unable to win any of the opening six races.
A protest from BMW after the Marrakech round earlier this month revealed that SEAT had been granted a variable increase in its boost pressure to counter atmospheric conditions in the first three races, which the rival manufacturers had not been informed about.
Theissen believes the WTCC's governing body, the FIA, is responsible for the situation and admits that there is no easy solution.
Last weekend at Pau, the row over the rules intensified as nine cars were excluded from qualifying for exceeding the maximum rev limit during downshifts. Fifteen cars then went unpunished for doing the same in the two races.
"This isn't so much a SEAT situation but an FIA situation," he added. "As far as we are concerned, it is extremely difficult to resolve.
"There were far too many decisions taken that were not clearly thought through. Sometimes after a race, and sometimes even during a race when the regulations were changed or the parameters were changed.
"The decisions taken were not communicated cleanly - that means competitors did not know what the situation was, and under which circumstances and conditions the other competitors were racing. This only became clear when there was a protest."
Theissen admitted that BMW is currently investigating opportunities in other touring car series and that it could choose not run a factory programme for an unspecified length of time.
"We are looking at other touring car categories," he said. "If we do come to a decision where a works commitment doesn't make sense in any given series, then it could be for a period of time that we may only lend support to our customers, as opposed to competing ourselves."