France is set to supply 23 H145 multipurpose Airbus helicopters for border patrols for 500 million euros (560 million dollars) to Saudi Arabia.
Saudi Deputy Crown Prince and Defense Minister Prince Mohammed Bin Salman met with French officials on Wednesday.
The contract is part of the 12 billion euro worth of deals struck between Paris and Riyadh.
Both countries had set up a joint commission in May to finalize around 20 projects in sectors ranging from defense to transport infrastructure and civil aviation.
France would begin feasibility study to assess constructing two nuclear reactors in Saudi Arabia, French Foreign Minister Laurent Fabius told reporters on Wednesday.
France relies on European Pressurized Reactors (EPR) considering it as the safest and most advanced in the world. The study is significant for Riyadh as its rival; Iran is developing its own nuclear capabilities.
Fabius also announced that Saudi Arabia have agreed on a commitment to acquire about 30 patrol boats built by DCNS, partly owned by Thales for its navy.
The signing in Paris comes as Saudi Arabia is seeking to bolster its military capabilities while it is leading a coalition against extremists in neighboring Yemen.
The trade relations in recent years have been greatly boosted. The bilateral trade has reached 9.4 billion dollars in 2013 with 8 percent jump from the previous year.