PARIS Oct 12 (Reuters) - France will use public money to recapitalise its banks if needed and will not have to fall back on the euro zone's EFSF rescue fund, government spokeswoman Valerie Pecresse said on Wednesday.Pecresse, France's budget minister, said the government would only use public money if banks that were revealed to have a capital shortfall were not able to raise the cash themselves from private investors.A July 21 agreement to allow the 440 billion euro EFSF to be used to recapitalise banks is still pending ratification by the last member of the 17-nation euro zone after Slovak legislators blocked it on Tuesday."Once the July 21 agreement is approved, the fund can be used to recapitalise banks, but France will not make use of the EFSF," Pecresse told a news briefing after a cabinet meeting which approved a state bailout of troubled Franco-Belgian lender Dexia .President Nicolas Sarkozy's government was thought to be wary of committing state funds to recapitalising banks -- due to the potential risk to France's triple-A credit rating -- and to prefer the use of the EFSF instead.Economists have suggested, however, that injecting billions of euros into French banks would not necessarily strip the euro zone's second largest economy of its coveted top rating, though weak growth could prove a greater threat."It looks as though the total amount of recapitalisation needed for French banks should be in the order of 10 to 20 billion euros, which is a relatively small amount," said Larry Hatheway, chief economist at UBS."That said, France is a very precarious AAA, particularly after the downgrade in the United States, and a downgrade may come anyway," he told an investor conference in Singapore.EUROPE TO ADOPT COMMON CAPITAL RULEFrance's government was confident that a second vote by the Slovakian parliament would approve modifications to the EFSF "very soon", Pecresse said, echoing similar comments by Foreign Minister Alain Juppe on Wednesday.Regarding the level of capital required of banks, Pecresse said that Europe would adopt a common rule, which would be announced at an EU leaders summit on Oct. 23."Today we have no doubt about the solidity of French banks but there is turbulence on financial markets which means an increase in capital for European banks has become necessary," she said.Paris was thought to prefer the use of the EFSF as a fallback option if private capital was not forthcoming, in contrast to Berlin which wants national governments to shoulder the burden.At a meeting on Sunday with German Chancellor Angela Merkel, however, Sarkozy said there was complete agreement between Germany and France on how to proceed, without providing any further details.Sarkozy has made retaining the triple-A rating, which ensures France borrows at rock-bottom rates on the market, a top priority but with economic growth slowing and elections in April, analysts have said his room for manoeuvre is narrowing.The law will call for France to guarantee up to 33 billion euros ($45 billion) in interbank and bond borrowing by Dexia and its Dexia Credit Local unit which provided the municipal government loans. Credit ratings agencies have said the move has no negative repercussions on France's triple-A rating.