The South Korean Defense Acquisition Procurement Agency (DAPA) has reportedly started the official bidding for the country’s KRW1.4trn ($1.26bn) aerial refuelling tanker programme.

An unnamed DAPA official was quoted by the Yonhap News Agency as saying: "The price bidding will continue until the end of this month.

"Price will account for around 20% of the total criteria."

Airbus Defence and Space , Boeing and Israel Aerospace Industries (IAI) are competing to sell four aerial refuelling aircraft to the Republic of Korea Air Force (ROKAF) between 2018 and 2019.

"The price bidding will continue until the end of this month."

While Airbus is offering an A330-based multi-role tanker transport, Boeing and IAI have pitched KC-46 Pegasus, and an advanced version of the B767-300ER aircraft, respectively.

According to DAPA officials, the agency will complete the evaluation by next month, and is expected to announce the contract in June.

South Korea has long been planning to acquire tanker capability to augment its air defence, but the plan has been repeatedly stalled due to budgetary constraints and changing priorities.

The new tankers are expected to help ROKAF fighter jets remain airborne for longer periods and increase their weapon-carrying capacity.

Specifically, the aircraft are anticipated to extend the operational range of ROKAF F-15K Slam Eagle and KF-16 fighter aircraft fleet, as reported earlier by the news agency.

The A330 is a military variant of the civilian Airbus A330-200 airliner that can perform air-to-air refuelling without any additional fuel tanks.

The KC-46 is based on the Boeing B767 airliner. It is a military aerial refuelling and strategic transport aircraft designed to operate in chemical, biological and nuclear conditions. It can also transport cargo, passengers and support aeromedical evacuations.

IAI’s upgraded B767-300ER aircraft will feature hose and drogue refuelling pods, a boom, or both, and will be modified for air-refuelling missions and transportation of supplies and military forces.