Ferrari and Renault have joined the Toyota and Red Bull teams who threatened to pull out of Formula One racing at the end of this season in protest over plans by the sport's governing body, the FIA, to push through an optional budget cap for the 2010 season.

Ferrari, which has competed every year since Grand Prix racing started in 1950, said this would lead to a two-tier championship, with those teams agreeing to limit their budget to EUR45m a year being allowed far greater technical freedom than those continuing with unlimited budgets.

The FIA has set a deadline of 29 May for teams wishing to compete in 2010 to submit entries and state whether they want a budget cap. It believes such a move could encourage up to three more teams to enter F1.

The Ferrari board said in a statement: "...if the regulations adopted for 2010 will not change, then Ferrari does not intend to enter its cars in the next Formula One Championship", adding that  the move by the FIA would see the introduction of two different sets of regulations based on arbitrary technical rules and economic parameters.

The Italian supercar maker said it would welcome moves to progressively reduce costs but the same rules must apply to all teams.

Renault team principal Flavio Briatore has adopted a similar stance. He said: "If the decisions announced by the FIA are not revised, we have no choice but to withdraw from the world championship at the end of 2009."

Ferrari booked an operating profit of EUR54m in the first quarter of this year compared to last year's EUR59m, reflecting the success of the California and Scuderia Spider 16M, the constant growth in activities linked to the brand and the company's continuing efforts to maximise efficiency, the board said.

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