Formula One's governing body said on Friday it would sue champions Ferrari and other teams for planning a breakaway series.
"The FIA's lawyers have now examined the FOTA (Formula One Teams Association) threat to begin a breakaway series," the International Automobile Federation (FIA) said in a statement at the British Grand Prix.
"The actions of FOTA as a whole, and Ferrari in particular, amount to serious violations of law including wilful interference with contractual relations, direct breaches of Ferrari's legal obligations and a grave violation of competition law.
"The FIA will be issuing legal proceedings without delay."
The eight FOTA teams announced on Thursday they would start preparations for their own championship after talks with the FIA over the 2010 rules broke down.
The governing body said it would continue with its own preparations for next year's championship but publication of the final entry list, due on Saturday, would now be put on hold pending the legal action.
The FIA maintains that Ferrari and the two Red Bull teams have pre-existing contracts to compete in their championship next year and registered them as unconditional entrants in an earlier list.
Ferrari have argued that contract no longer applies because the FIA has not respected its right to veto the technical regulations.
The Italian team, whose departure would end an unbroken 60 years of competition in the FIA world championship, took legal action against the FIA in France last month to try to prevent the governing body from imposing a budget cap in 2010.
Four years ago, Ferrari broke ranks with other manufacturers planning a rival grand prix series and agreed to commit to the FIA's championship until the end of 2012.
"In 2005 we signed an exchange of letters with them saying that their rights and privileges under the Concorde Agreement would continue until 2012, whether or not we signed a new one," FIA president Max Mosley said last month.
"They were in a position where they had whatever they had under the old 1998 Concorde agreement in return for being loyal."
He maintained then that Ferrari had effectively forfeited their right to veto the technical rules by forming FOTA, chaired by Ferrari president Luca di Montezemolo, last year.
"It would be our contention that they walked away from this agreement some time ago," said Mosley.
"Essentially, they walked away by forming FOTA. They were always supposed to be loyal to the FIA, work with us and co-operate."