Raytheon Missle Systems has received a $350 million contract from the U.S. Department of Defense for the newest model of its SM-3 missile.

The Pentagon ordered 44 items from Raytheon, including the missile and accompanying materials. The government's total order for the previous model was eight.

"We manufacture key components of the SM-3 right here in Tucson," said John Patterson, senior manager public relations and community relations at Raytheon. "This contract helps us maintain our operations and expand if business conditions warrant that."

Patterson said the company does not know yet how the new contract will affect staffing levels at the Tucson plant.

The SM-3 is used by the U.S. Navy to intercept incoming short-to-intermediate-range missiles.