Singapore has already signed a contract to acquire six A330 multirole tanker transports (MRTT), Airbus Defence & Space has confirmed, the day after its customer announced the selection of the type.

"The aircraft will be delivered under the terms of a firm contract which has already been signed," the European company says, without providing further details such as the deal's value. Deliveries are due to commence in 2018.

Acquired to replace an in-service fleet of four Boeing KC-135Rs, the A330 tanker/transports will deliver a significant capability increase to the Republic of Singapore air force.

Confirming the type's selection during a presentation on long-term defence plans made to parliament on 6 March, defence minister Ng Eng Hen noted: "The MRTT can hold 20% more fuel than our current KC-135s and will extend the range of our fighters through air-to-air refuelling. The Airbus A330 can also double up as a cargo and troop-lift aircraft to deploy troops and equipment to overseas sites further away, as we have done in HADR [humanitarian assistance and disaster relief] operations."

A fact sheet prepared by Singapore's defence ministry reveals that the nation's aircraft will be powered by Rolls-Royce Trent 772B engines, and delivered with a 266 seat-configured passenger cabin.

Ng also referred to the air force's current Boeing F-15SG and Lockheed Martin F-16 combat aircraft – the latter of which are to receive an active electronically scanned array radar upgrade – plus a fleet of next-generation fighters which will be in operation before 2030. "We are not quite ready to decide yet. We will take our time because our F-16s and F-15s will serve us for the near term and medium term," he adds.

An existing A330 tanker operator has recently secured qualification to refuel the F-15, according to an industry source.

Singapore holds security co-operation participant status in the Lockheed Martin F-35 Joint Strike Fighter programme, and has shown recent interest in the short take-off and vertical landing B-model.