Manufacturers BMW and Honda have decided to drop their legal challenge to the FIA's proposed engine regulations, due to be introduced in 2006, claiming that the decision is in "the best interests of the sport".

BMW, Honda and Mercedes were to take the FIA to arbitration following the FIA's decision to introduce a new 2.4 litre V8 engine configuration in 2006. The FIA believes that the move will reduce costs, whilst the manufacturers claim it will have the opposite effect. Ferrari, Cosworth and Renault have all accepted the new regulations.

"The BMW WilliamsF1 team has decided, in accord with BAR Honda, not to appeal against the engine regulations, scheduled for 2006," said BMW Motorsport director Mario Theissen. "A legal challenge to the content and form of the modified regulations would take up too much time, time in which all manufacturers would be forced to undertake costly parallel developments.

"That would not be in the interests of the sport, whose future we aim to strengthen," he added. "With this decision we want to contribute to a united position of the engine manufacturers in Formula One."

Thus far, there has been no reaction from Mercedes, though it's thought that they too will fall in line with their rivals.