French automaker Renault announced earlier that its board of directors had not reached a decision following a crunch meeting held at the request of the French state, the biggest shareholder in Renault with a 15 percent stake.
Then the great plan came crashing down, with Bloomberg News reporting in the small hours of Thursday that Fiat had withdrawn its offer.
In a statement, Fiat alluded to the dispute and said it "has become clear that the political conditions in France do not now exist" for the deal.
Fiat Chrysler cited "political conditions in France" for the withdrawal, but it thanked both alliance partners for "their constructive engagement".
Saikawa said in a statement that the Renault-Fiat Chrysler deal would "significantly alter" the structure of Nissan's longtime partnership with Renault, and Nissan would analyze its contractual relationships to protect the company's interests.
When FCA was run by Sergio Marchionne, who died past year, the company made several attempts to buy or merger with rivals.
"FCA will continue to deliver on its commitments through the implementation of its independent strategy", FCA said.
Fiat Chrysler, an Italian-American company, withdrew from a 50-50 merger proposal for its French rival after a board meeting on Wednesday.
The merger talks collapsed Wednesday night after the French government - Renault's top stakeholder - asked for more time to get support from Renault partner Nissan.
As we've reported in the past, the USA government has been investigating Fiat Chrysler Automobiles for some time now over its sales reporting methodology.
The combined company would produce some 8.7 million vehicles a year, more than General Motors and trailing only Volkswagen and Toyota.
That was not enough for the government, which asked FCA for more time to go back to Japan to persuade Nissan to support the deal.
Earlier Wednesday, France's finance minister said the vehicle companies shouldn't rush into a merger.
The French government, which controls 15 percent of Renault, gave it a conditional green light but also warned against "haste". The company didn't explain why, but a French government official said board members don't want to rush into a deal and are seeking agreement on all parts of the potential merger.
Le Maire is traveling to Japan this weekend to meet with Nissan officials on a previously arranged visit.
Bigland claims he just cooperated with the SEC investigation by testifying about FCA's sales reporting, from the time he took the position to the period prior to being appointed the company's US sales chief.
Le Maire told BFM TV on Wednesday that it was now up to judicial authorities to take the next decision.
If Renault's board says "yes" to Fiat Chrysler, that would open the way for a non-binding memorandum of understanding to start exclusive merger negotiations. "I won't comment further, if FCA withdrew its offer it's because it didn't see an economic advantage, or other type of advantage", Deputy Prime Minister and 5-Star leader Luigi Di Maio told Italian state radio.