Former French Prime Minister Alain Juppe has resigned his post as president of France's ruling UMP party.
Juppe was seen as a potential successor to President Chirac
His resignation opens the way for
a succession battle at the head of President Jacques Chirac's party.
Ambitious Finance Minister Nicolas Sarkozy is vying for the party leadership, although Mr Chirac has said he would not be able to remain a minister and lead the party.
Juppe had been expected to step down after being convicted of corruption.
"Today I move away from political life in order to make peace with myself after the torment I have just been through," he said in an open letter to party members released by the UMP.
A new party leader will be chosen at a party congress in November.
Mr Sarkozy has not yet officially declared himself a candidate for the post.
Juppe received an 18-month suspended prison sentence, and was also barred from public office from 10 years earlier this year.
The charges related to a jobs scam at Paris City Hall while Mr Chirac was mayor.
Juppe has appealed against his conviction, but an appeal hearing will not take place until mid-October. In the meantime, the penalties he faces are suspended.
He remains a member of parliament and the mayor of Bordeaux.
A close ally of Mr Chirac's, Juppe was considered a favoured choice to succeed him as president.