UPDATE 1-Areva office, former staff's homes searched in UraMin probe
* Financial prosecutor searches Areva headquarters
* Search part of inquiry into 2007 UraMin acquisition
* Former Areva CEO Anne Lauvergeon's residence searched (Updates with court confirmation of more searches)
PARIS, June 3 (Reuters) - State-controlled nuclear group Areva's headquarters and the homes of former executives were searched on Tuesday by France's financial prosecutor as part of an investigation into Areva's $2.5 billion acquisition of Canadian uranium mining company UraMin in 2007, a judicial source said.
The source told Reuters that a total of 11 searches had been carried out, including at the home of former Areva CEO Anne Lauvergeon and Areva's former mining director Sebastien de Montessus.
Lauvergeon and de Montessus were not immediately available for comment.
"Our headquarters in the La Defense district have been the object of a search by the financial prosecutor following the referral by the state auditor. The company is cooperating," an Areva spokesman said.
The prosecutor has opened an investigation into the UraMin acquisition after state auditor Cour des Comptes - a quasi-judicial auditor that oversees state accounts - referred the case to the prosecutor following its audit of Areva's accounts between 2006 and 2012.
In a preliminary report leaked to the French press last month, the auditor gave a withering review of Lauvergeon's management of Areva.
The report said that insufficient oversight and even "dissimulation" were among the reasons for Areva's ill-fated 2007 acquisition of uranium mine UraMin, on which it later to wrote down 1.9 billion euros.
French daily Le Monde has reported that the prosecutor is investigating possible "presentation or publication of inaccurate or untrue accounts", "distribution of false or misleading information", and "forgery".
Lauvergeon last month rejected the auditor's criticism of her and said she had made no mistakes.
Lauvergeon, who ran Areva from 2001 to 2011 and who was ranked as the world's 9th most powerful woman in 2008 by Forbes magazine, blamed the UraMin writedown on the impact of the 2011 Fukushima nuclear disaster on uranium demand. She played down reports that the uranium content of the Africa-based mines are much lower than the sellers had led Areva to believe.
At the time of the 2007 acquisition, Lauvergeon described the deal as "a major step in Areva's ambitious plan to increase its uranium production".
Uranium prices subsequently fell and UraMin's reserves, mostly in southern and central Africa, turned out to be lower than initially estimated, forcing Areva to take a writedown of close to 1.9 billion euros over the years 2010 and 2011.
After Lauvergeon left Areva in 2011, an internal audit into the deal did not reveal fraud, but said that presentations made to state holding company APE and to Areva's board about the planned UraMin acquisition had not given enough prominence to the doubts that the internal technical teams had expressed. (Reporting by Geert De Clercq, Gerard Bon and Nicolas Bertin; Editing by James Regan)