French authorities have charged the husband of French nuclear giant Areva's former boss Anne Lauvergeon with insider trading as part of a probe into its 2007 purchase of a Canadian uranium mining firm, a legal source said Wednesday.

Energy sector adviser Olivier Fric was charged on March 23 after the finance ministry's intelligence unit homed in on him, a source told AFP.

The ministry unit known as Tracfin suspected he was able to take advantage "of information which the other stock market players didn't get" on Areva's purchase of the uranium miner Uramin, the source added.

The unit had been investigating the buying of Uramin shares by a Swiss company that Fric and an associate owned.

A ministry document indicated that shares had been bought between May and June 2007, shortly before the official June 15, 2007 announcement of a takeover of Uramin by Areva.

Five days later, the shares were resold as a bloc, leading to a net profit of nearly 300,000 euros ($340,000 at the current rate).

Fric was also suspected of wanting to hide the operation via bank accounts that did not show he was the holder.

His lawyer denied Fric had profited from inside information.

"My client has never worked at Areva nor for Areva," lawyer Mario Stasi told AFP.

"He has never been the beneficiary of any information on the management or strategy of the group which isn't publicly available."

Lauvergeon, Areva's former chief executive who ran the firm when the sale took place, has told the Parisien newspaper that "confidentiality rules at Areva were very strict".

The charges against Fric are part of a wider probe into the $2.5 billion (1.8 billion euros at the time) purchase by Areva of Uramin at a height of demand for enriched uranium.

Areva was later forced to revalue its Uramin uranium mines to only 410 million euros.

Several mines in Africa were never run.

Anne Lauvergeon, 56, was a key economics advisor to the late French president Francois Mitterrand before being named to head nuclear energy agency Cogema which she merged with Framatome to form Areva. She left Areva in 2011.

She has been included in Forbes's list of the world's most influential women.

She currently heads a government-appointed "Innovation Commission".