(Adds Le Figaro on value of Areva NP)
By Benjamin Mallet and Yann Le Guernigou
PARIS, July 21 (Reuters) - The French government set out a timetable for the tie-up between utility EDF and Areva on Tuesday as sources said the cost of recapitalising the struggling nuclear reactor maker could be double what was previously expected.
Economy Minister Emmanuel Macron told a parliament committee details would be announced on July 31, with a recapitalisation plan to be set out in September.
"We will open a new operational phase on the new Areva on July 31 ... with a date in September on additional subjects including Areva's recapitalisation," he told a parliament committee.
A source close to the matter said the amount needed for Areva's capital increase, needed after four years of losses, was higher than previously expected by the French treasury at Bercy.
"There was a very bad surprise for Bercy on the amount of the capital increase. The government was hoping for one or two billion euros, and it might be more than double that," the source said.
A second source with knowledge of the matter confirmed the figures, and said the final figure would depend on negotiations between the two parties over nuclear fuel recycling and other commercial contracts.
EDF and Areva declined to comment on the subject.
Macron also said the risks coming from Areva's troubled EPR project in Finland, where the French company is locked in a dispute on delays and cost overruns with a Finnish utility, will not be passed on to EDF, but could not be left to Areva alone.
It could therefore end up as a liability for French taxpayers. "Considering the amounts involved, we know very well that the majority shareholder (the government) will have a role to play," the minister said.
EDF CEO Jean-Bernard Levy said earlier this week he expected to reach a deal to buy the nuclear reactor business of loss-making Areva by the end of July.
"The talks are well advanced, everybody has agreed on a price," a source close to the talks said, without giving a figure.
Le Figaro said in its Wednesday edition, citing unnamed sources, it would be near 2.7 billion euros ($2.93 billion), rather than the 2 billion euros initially offered by EDF.
A firm offer from EDF will not come before the end of October, the source said.
Areva, which is 87 percent owned by the French state, is due to release first-half results on July 31.
(Reporting by Yann Le Guernigou and Benjamin Mallet; writing by Michel Rose; Editing by Andrew Callus and Alan Crosby)