Details were added (the first version was posted at 21:43)
French Foreign Minister Michele Alliot-Marie resigned on Sunday, the broadcaster BFM reported.
Her departure was expected, following a scandal over her recent holidays in unrest-beset Tunisia, dpa reported.
President Nicolas Sarkozy is expected to discuss the government reshuffle on Sunday night during a nationally televised speech.
Defence Minister Alain Juppe is expected to replace Alliot-Marie. Government sources said that Interior Minister Brice Hortefeux will also swap positions with Sarkozy's general secretary, Claude Guean.
Alliot-Marie, 64, had headed several ministries since 2002 and was considered to be an extremely competent politician. She had taken over the defence portfolio some 100 days ago.
But she became embroiled in a conflict-of-interest controversy after taking a holiday in Tunisia at the same time that the popular uprising there was starting to get underway in December.
At the time, she offered police support for the embattled regime of president Zine El Abidine Ben Ali - who later was forced from power and fled Tunisia amid the uprising - while also accepting a flight on a private jet of a person close to the leadership.