"This agreement, financed through Saudi aid, will contribute to strengthen the Lebanese army, guarantor of Lebanon's unity and stability (...) at a time when Lebanon is under threat" said French Foreign Minister Laurent Fabius.
The deal comes as the poorly-equipped Lebanese army fights jihadists - including militants of the so-called Islamic State group or Daesh - along its border with Syria and its main northern city Tripoli, rocked by fighting between troops and suspected Al-Qaeda loyalists.
The agreement was signed in Riyadh by Saudi finance minister Ibrahim al-Assaf and Edouard Guillaud, the head of the ODAS organisation set up by France to export defence equipment.
Fabius also called on Tuesday for the US-led coalition against Daesh to help rebels in Syria's second city Aleppo.
"Assad and Daesh are two sides of the same barbaric coin" said Fabius, "the coalition should not not battle IS to the exclusion of supporting rebels fighting President Bashar al-Assad's regime" he added.