SEOUL, South Korea — U.S. and European aircraft makers are gearing up for South Korea’s $1.8 billion contest to acquire new maritime patrol aircraft.

South Korea has long sought to boost its fleet of maritime patrol and surveillance jets in response of North Korea’s naval capabilities, including submarine-launched ballistic missiles.

The Defence Acquisition Program Administration plans to issue a request for proposals to foreign aircraft makers as early as May, DAPA spokesman Kang Hwan-seok said. The government is looking to buy at least six maritime patrol aircraft, or MPA, in addition to the existing fleet of 16 P-3Cs, he added.

“The RFP is expected to be issued when the DAPA’s executive committee makes a final decision over the method of acquiring MPA in late April or early May,” Kang said. “We’re now reviewing information of potential candidate aircraft.”

The DAPA originally considered a private contract with Boeing for the P-8A Poseidon, as there were no tangible rivals, but European aircraft makers are ready to throw their hats in the ring.

Sweden’s Saab is the most aggressive among the European contenders. The firm pitches the Swordfish MPA variant built on the airframe of the Bombardier Global 6000 business jet.

“Saab GlobalEye, an airborne early warning and control aircraft, has completed its first flight successfully,” an official representing Saab’s MPA campaign told Defense News on condition of anonymity.

“GlobalEye was built on the Bombardier Global 6000 jet, the same platform for the Swordfish, and shares mission systems and sensors as much as 80 percent with those of the Swordfish,” the official said. “So there is not a single problem for the Swordfish to compete for the South Korean MPA contest and undergo due test and evaluation procedures.”

The Global 6000 configuration has a maximum cruise speed of 450 knots and a long-range cruise speed of 360 knots. According to Saab, the Swordfish, which is not yet in production, can be equipped with an active electronically scanned array radar that has a 360-degree detection capability, six torpedoes and anti-ship missiles.

Saab is ready to offer South Korea an opportunity to take part in the development and construction of Swordfish planes, according to the official. “We could propose South Korea build two to three of the initial Swordfish planes in Sweden, with the rest being assembled in South Korea,” the official said.

“This opportunity will help South Korea to build its own maritime patrol aircraft platform in the future.”

Airbus is said to offer either the C295 MPA or the militarized A320neo built for maritime warfare. Airbus Defence and Space, the defense unit of the European aerospace giant, held a news briefing at Gimpo Airport in July, ahead of the Seoul International Aerospace and Defense Exhibition, to offer a potential candidate aircraft for South Korea’s MPA procurement effort.

During the briefing, an Airbus representative touted the C295 MPA fitted with Elta Systems AESA as a potential candidate for the South Korean Navy’s new MPA fleet. Airbus, however, has yet responded to the DAPA’s request for information on the MPA program, according to the agency.

Despite competition, Boeing is still confident about the P-8’s ability to stand out against against European contenders.

“The P-8 is proven, already deployed around the world and designed for multiple missions: anti-submarine warfare, anti-surface, ISR, and search and rescue,” said Matt Carreon, global sales and marketing lead for the P-8 program. “It’s the only maritime patrol aircraft in operation today that enables complete interoperability between the U.S. and its allies.”

Modified from the 737-800 commercial jetliner, the P-8 can carry four anti-ship missiles, five torpedoes and 129 sonobuoys. The plane can fly 1,200 nautical miles and remain on station for more than four hours. It can reach a maximum altitude of 41,000 feet.

Canada’s KP-X MPA, built using the the Bombardier Challenger 650 platform, may also prove a contender in South Korea’s procurement effort.

“Field Aviation and General Dynamics Mission Systems of Canada have for decades been recognized as leaders in providing special-mission aircraft modifications and innovative anti-submarine warfare and maritime security solutions, respectively,” said Hwang In-kew, head of Hanbaek Aerospace, an agency for the Canadian firms’ MPA campaign in Seoul.

The aircraft’s endurance is in excess of 11 hours, Hwang said, adding that the company could offer 15 aircraft within the $1.8 billion budget.

“We already provided information on the KP-X to the DAPA,” he said. “Upon final requirements — including armament — being released, we’ll be able to make a decision on whether or not we can compete for the MPA program.”