Former French president Nicolas Sarkozy has been cleared of allegations he illegally took donations from France's richest woman on the way to his 2007 election victory.
The announcement fanned speculation of a political comeback for Mr Sarkozy, who lost the presidency to Francois Hollande last year.
"I am delighted about this decision, which I expected," Mr Sarkozy's lawyer Thierry Herzog said.
Ten other people - including Mr Sarkozy's former budget minister, Eric Woerth - are still expected to face trial next year on charges in the case that include alleged fraud and money laundering.
A former Bettencourt accountant told police she handed over 150,000 euros in cash that she was told would be passed to Woerth, who was Mr Sarkozy's campaign treasurer for the 2007 presidential bid. That was well over the maximum allowed campaign contributions under French law.
After reports of the illegal campaign cash first surfaced in 2010, investigators gradually pieced together their case, coming closer and closer to Mr Sarkozy himself. In March this year, he was handed preliminary charges, meaning that magistrates had reason to believe wrongdoing was committed. But after deeper investigation, the case against him collapsed because of lack of evidence.
"The dismissal is good news, but I am not surprised because this case file was totally empty," said Patrick Balkany, an MP and Sarkozy friend. "The surprise was that he was under investigation at all. Slapping preliminary charges against a former president is no small thing."
Mr Sarkozy, 58, has drifted out of the political arena but polls show he is still popular among his fellow conservatives, whose UMP party is riven with infighting. He has been seen more often in public in recent weeks, prompting talk that he might run for president again in 2017.
While he is off the hook in the Bettencourt affair, his name has surfaced in other investigations.
Relatives of French victims of a deadly 2002 bombing in Pakistan brought a complaint in Paris last year against Mr Sarkozy and two former advisers for allegedly violating a duty to secrecy in an investigation of the case. The Karachi car bombing killed 15 people, mostly French defence contractors.