* Leaders say everything must be done to try to save A400M
* Germany says differences narrowed over "financing"
* Source says parties still 2.4 billion euros apart
* Further talks offered on loans, inflation link
(Recasts after Berlin meeting)
By Sophie Hardach and Dave Graham
PARIS/BERLIN, Feb 4 (Reuters) - France and Germany called for urgent solutions to a funding crisis over Europe's biggest military project, the A400M troop plane, but talks on Thursday between Airbus and NATO nations failed to agree a quick bailout.
Technical problems have pushed the 20 billion euro ($27.75 billion) project four years behind schedule and 11.2 billion euros over budget, threatening up to 10,000 jobs and sparking testy exchanges between the leading buyer Germany and Airbus.
French President Nicolas Sarkozy and German Chancellor Angela Merkel spoke out following a summit in Paris, but stopped short of a formal declaration as gaps remained among negotiators at seven-nation talks in Berlin.
"Everything must be done to reach a solution. It is a decisive project which must be resolved very quickly," French President Nicolas Sarkozy said at a joint news conference after the Franco-German summit.
"With regards to the A400M project, I think that the negotiations should be continued, and we agreed that this is a project of strategic significance, and that everything should be done to find a solution," German Chancellor Angela Merkel said.
The A400M is designed to put soldiers and heavy equipment in rugged combat zones like Afghanistan, and some backers see it as a prop to Europe's efforts to forge its own defence identity.
Other buyers of the plane are Britain, Belgium, Luxembourg, Spain and Turkey.
As Sarkozy and Merkel met, Airbus owner EADS resumed talks with European government buyers in Berlin in a frantic bid to prevent the soaring costs killing off the project.
The group faces major A400M provisions in its 2009 earnings and an industry source said a quick solution was needed by the company's auditors. EADS declined official comment.
EADS has appealed to the buyers for extra support to start full production of the plane, which first flew in December. But governments are unwilling to let taxpayers foot the whole bill.
2.4 BILLION EURO GAP
A German defence spokesman said Berlin talks had narrowed differences over financing, but did not say whether this referred to loans that are part of the discussion. "There was a narrowing of positions on the subject of financing," he said.
"The buyer nations and EADS agreed to continue talks over the remaining gap as quickly as possible," he added.
However a person familiar with the matter said the two camps had failed to bridge a 2.4 billion euro gap in core demands.
Talks broke off last week after EADS sought 4.4 billion euros to keep the project afloat while buyers offered 2 billion.
In Berlin on Thursday, buyers "confirmed the 2 billion euro offer and (are) ready to discuss other financing options," according to the person familiar with the matter, who spoke on condition of anonymity due to the sensitivity of the talks.
Nations offered EADS talks on a package of credits or loans but no concrete proposal, the person said.
They also offered talks to address an inflation formula which EADS has been pressing buyers to adjust.
EADS shares fell more than 2 percent to 14.25 euros.
Airbus recently threatened to shut down the A400M if a deal could not be reached soon, risking a major confrontation with countries that call most of the political shots at EADS.
EADS is controlled jointly by French and German interests and the French and Spanish governments directly own stakes.
Germany's defence minister, who has taken a harder line than most on the row, warned the firm against overplaying its hand.
"There is a contract and we have an interest in not allowing ourselves to be pressured unduly," Karl-Theodor zu Guttenberg told reporters in Paris after the Franco-German summit.
Guttenberg was speaking before heading off to Istanbul for a meeting of NATO defence ministers, part of a flurry of meetings being held across Europe that could determine the A400M's fate.
U.S. rival Lockheed Martin has said it expects to sell more C-130J Hercules planes due to A400M delays and analysts say a collapse could also benefit Boeing, whose larger C-17 jet-powered transporter faces a U.S. budget threat.
(Additional reporting by Tim Hepher, Tracy Rucinski, Julien Toyer, Matthias Blamont and Rene Wagner; Editing by Greg Mahlich and Elaine Hardcastle)