Northrop Grumman is to produce 25 more E-2D Advanced Hawkeye early warning aircraft for the U.S. Navy under a multi-year contract, the company announced.

The E-2D, which provides 360-degree surveillance capability though the use of AN/APY-9 radar, was specifically designed for use from an aircraft carrier.

"The E-2D Advanced Hawkeye is the Navy's primary airborne early warning and battle management command-and-control platform," said Navy Capt. John S. Lemmon, program manager, E-2/C-2 Airborne Tactical Data System Program Office. "I'm confident that as the E-2D Advanced Hawkeye attains initial operational capability later this year, the E-2D will continue to be ready, relevant and capable for decades to come and continue serving the Navy Carrier Strike Group with distinction."

The contract for 25 of the planes brings the number on order by the Navy to 50. The fixed-price, incentive-fee award is worth $3.6 billion, Northrop Grumman said.

"A multiyear procurement of these additional E-2Ds will take advantage of efficient, stable production lines at both Northrop Grumman and our suppliers, and will generate significant cost savings for taxpayers and the Navy," said Bart LaGrone, vice president, E-2/C-2 Programs, Northrop Grumman Aerospace Systems. "It's a win-win -- our warfighters will get the advanced AEW&C technology that the E-2D Advanced Hawkeye brings, at a lower cost for taxpayers."

The aircraft has a cruise speed of 252 knots and a six-hour mission endurance. The original E-2 model entered service in 1964. Northrop has so far delivered 13 of the new, advanced variant.