Raytheon, one of the largest US weapons makers, is expected to sign an estimated $2.1 billion deal to sell Oman an air defense system while US Secretary of State John Kerry visits the Sultanate state this week, US officials said.

One official, who spoke on condition of anonymity, told reporters the company was expected to sign a letter of intent with Oman to provide a ground-based air defense system.

The official said the terms were still being negotiated and the deal's value was not yet final according to Reuters.

Meanwhile, the U.S. Air Force has awarded Raytheon a contract to build rapidly deployable air traffic control (ATC) systems that can be delivered anywhere in the world and then be fully operational controlling flights within six hours.

The contract, with a potential full value of $260 million, calls for one Engineering and Manufacturing Development unit plus production options for up to 18 Deployable Radar Approach Control (D-RAPCON) systems. The Air Force has authorized Raytheon $50.6 million for the early development stage. Ten of the units will be delivered to the Air National Guard, seven to the active-duty Air Force Space Command, one to the Air Force ATC School and one to the Air Force depot.

D-RAPCON provides sequencing, separation of aircraft, navigation assistance and airspace control services, all with the latest digital sensors, communications equipment and advanced surveillance data processing systems. The Raytheon solution shares many common elements with existing U.S. Department of Defense ATC infrastructure.

D-RAPCON consists of a transportable antenna plus three trailer-sized shelters that house radar equipment, communications systems, and an operations center with multiple controller work stations. Each station has the same look and feel of what a controller would see at a major airport.

The Raytheon technology builds on proven subsystems, including the Digital Airport Surveillance Radar (DASR) and the Standard Terminal Automation Replacement System (STARS). U.S. Air Force air traffic controllers are trained and certified on STARS, the same automation system they use at the fixed-base ATC sites.