French nuclear giants Areva and EDF will merge their reactor businesses in a joint venture controlled by EDF — a wide-ranging reshuffle of the country's state-owned atomic energy industry.

French President Francois Hollande's office announced the deal's broad outlines Wednesday, saying final details would be negotiated by the two companies within a month.

The French government, which controls over 80 percent of both companies, will inject new capital "of the necessary amount" in Areva as part of the deal.

The outcome is a major reversal for Areva, whose ex-CEO Anne Lauvergeon fought off attempts to marry her company and EDF for years.

Areva lost nearly 5 billion euros ($5.6 billion) last year after taking a massive loss on new reactor projects in France and Finland.