Raytheon employees in Tucson will lead the way on work for the United States Navy’s Evolved Sea Sparrow Missile system after a $13.7 million contract modification was awarded to the company on Wednesday.

More than 90 percent of the work will be done in Tucson, according to a press release announcing the decision. Work will also occur in the Netherlands, Norway, Germany, and Australia, in addition to sites in West Virginia, Canada, Spain, and Turkey.

The missile program is described as an international cooperative effort and is a medium-range surface-to-air system designed to protect ships from missiles and attacking aircraft. Development of the Sea Sparrow program began with NATO in 1990, and Raytheon delivered the first production system to the Navy. The missile entered into service in 2004.

Work on the current project is expected to wrap up in December and the contract includes purchases for the Navy and the governments of Thailand, Japan, and the United Arab Emirates.

Raytheon was originally awarded the contract in 2016 at a potential value of $197 million.