The former French prime minister, Dominique de Villepin, has been cleared of involvement in a conspiracy to smear Nicolas Sarkozy and sabotage his campaign to become president in 2007.
Mr de Villepin who became prime minister in 2005 after stints as foreign and interior minister, had been accused of using faked documents to link Mr Sarkozy to a corruption probe.
He always denied the charges in the so-called Clearstream case, and said repeatedly that he was a victim of a vendetta by Mr Sarkozy.
In a ruling read out to the packed courtroom, a judge said there was no firm evidence that the former prime minister had tried to discredit Mr Sarkozy or that he had acted in bad faith.
However, three other defendants were found guilty of conspiracy.
The former prime minister holds no elected post and works as a lawyer. However, he still has supporters on the centre-right and members of his inner circle have said he should challenge Sarkozy in the 2012 presidential election.
Three found guilty
The judge said Jean-Louis Gergorin, a former executive at aerospace company EADS who had links to intelligence services, and Imad Lahoud, a computer specialist, were the main architects of the affair.
Gergorin was sentenced to 15 months in prison and Lahoud to 18 months.
Florian Bourges, a former Arthur Andersen auditor who obtained the original documents, was found guilty of theft and breach of trust but the journalist Denis Robert, to whom he gave them and who later showed them to Lahoud, was cleared.