UPDATE 2-Motor racing-Threat of F1 breakaway series revived

* FOTA say F1 future in jeopardy

* FOTA teams walk out of meeting with FIA

* Others agree changes to 2010 rules (Adds background)

By Alan Baldwin

LONDON, July 8 (Reuters) - The threat of a breakaway Formula One series loomed again on Wednesday after Ferrari and seven other teams walked out of talks in Germany with the governing body and warned that the sport's future was at risk.

"The eight FOTA (Formula One Teams Association) teams were invited to attend the meeting to discuss their further proposals for 2010," the International Automobile Federation (FIA) said in a statement.

"Unfortunately, no discussion was possible because FOTA walked out of the meeting."

FOTA, who had threatened to set up their own championship until what seemed to be a breakthrough deal was announced in Paris last month, said in a statement that the future of Formula One was again "in jeopardy".

FOTA's members are championship leaders Brawn GP, BMW-Sauber, Ferrari, McLaren, Red Bull, Renault, Toro Rosso and Toyota.