New Zealand has awarded a major air force upgrade contract to the U.S. aviation company Boeing. The contract is worth 26 million U.S. dollars.

It includes upgrading the underwater, intelligence, surveillance and reconnaissance capabilities of six Orion aircraft of the country's air force to improve surveillance of submarines. New Zealand businesses will also be involved in  the upgrade, taking around 25 percent of the value of the contract.

Work has been underway to select a replacement for the Orion aircraft that is due to retire from service in around 10 years' time.