The former PMs – Jean-Pierre Raffarin, Alain Juppe and Francois Fillon – took "provisional control" of the conservative UMP following a unanimous vote by party mandarins.
The UMP has struggled to unite behind a single leader since Sarkozy stepped down after losing the last presidential election in 2012.
Its most recent leader, Jean-Francois Cope, was forced to resign late last month following claims that €10 million ($13.6 million) spent on Sarkozy's failed 2012 re-election bid were fraudulently billed as party
The new triumvirate will lead the party until its autumn congress, when a permanent president will be elected.
"A group decision, a clear mandate, for unanimity: beautiful evening for the UMP!" tweeted Fillon.
"The UMP is saved," added Raffarin.
But the party still finds itself bitterly divided, with Juppe, Fillon and Sarkozy all seen as potential contenders for a run at the presidency.
To date, Sarkozy has not been implicated directly in the funding scandal, but it has nonetheless been interpreted as another blow to his chances of staging a comeback in time for the 2017 presidential election.
Author Jean-Baptiste Marteau, co-author of a book about the UMP called "A Merciless Universe", said only time will tell if the UMP can recover from the crisis.
"They need to restore the confidence of the militants in the UMP. The good thing for them is that this comes three years before the next presidential election. If it had been six months then it would have been impossible to repair the damage," Marteau told The Local.
As for whether Copé's resignation will harm or boost the chances of Sarkozy making a comeback, the author says it's too early to tell.
"Sarkozy's entourage say he had nothing to do with this affair and that's he's furious. But at some point he will have to speak about it publicly. It appears the way is open for him.
"In terms of running for the presidency it seems onmly Alain Juppé, François Fillon or Nicolas Sarkozy have a chance of running in 2017," Marteau said.
For his part, Copé himself, has insisted on his innocence.
Speaking on TV last month, Copé asked France not to doubt his integrity, adding that employees had "abused" his trust.
Copé, said he would “turn the page” after the scandal, dubbed the Bygmalion affair after the name of the PR firm that was authorizing the phony invoices.
“I will now handle politics differently, but always with the same idea that has always driven me, which is my love for my country and serving the French people,” Copé told TV viewers.
“I ask the French not to doubt my integrity. My honesty is total,” said Copé before blaming his colleagues in the party.