WASHINGTON (Reuters) - The U.S. government on Friday said it has approved $2.5 billion in modifications and upgrades of used U.S. military vehicles that are to be sold separately to the United Arab Emirates as "excess" equipment.

If finalized, the work would be done by Navistar International Corp, Britain's BAE Systems and Oshkosh Corp, the Pentagon's Defense Security Cooperation Agency said in a notification to Congress.

The agency, which oversees foreign arms sales, said the deal would help UAE protect its troops, better provide humanitarian assistance, and protect vital commercial trade routes.

The Pentagon agency said UAE had requested the refurbishment and modification of 4,569 Mine Resistant Ambush Protected (MRAP) vehicles, which are to be sold separately to UAE as excess U.S. military equipment.

The potential deal also includes kits to improve the underbodies of the vehicles, spare and repair parts, support equipment, and personnel training and training equipment, DSCA said.

Once a weapons sale is approved, it must still be negotiated by the two governments.

(Reporting by Andrea Shalal; Editing by David Gregorio)