FILE PHOTO: The Boeing logo is pictured at the Latin American Business Aviation Conference & Exhibition fair (LABACE) at Congonhas Airport in Sao Paulo, Brazil August 14, 2018. REUTERS/Paulo Whitaker

WASHINGTON (Reuters) - The U.S. Air Force awarded Boeing Co BA.N a $376 million contract to build four helicopters in the first leg of a $2.38 billion deal to replace the fleet of 46-year-old UH-1N Huey helicopters.

The Air Force said it will eventually order 84 helicopters to be delivered from 2020 through 2032.

The Air Force will use the helicopters to protect the U.S. nuclear arsenal, with aircraft based in Wyoming, Montana and North Dakota, among other locations around the world.

Boeing said its MH-139 helicopter is based on Italian aircraft maker Leonardo SpA's LDOF.MI AW139, which is used by more than 270 governments, militaries and companies around the world.

The helicopters will be built at two facilities outside of Philadelphia.

“Strong competition drove down costs for the program, resulting in $1.7 billion in savings to the taxpayer,” Secretary of the Air Force Heather Wilson said.