Sir John Key will step down from the board of Air New Zealand on March 31, the company says.

Chair Dame Therese Walsh says Key indicated earlier this year that 2020 would possibly be his last as a Director due to increasing commitments on his professional time in New Zealand and overseas.

Walsh says Key has made a significant contribution to Air New Zealand.

"Sir John's outstanding commercial acumen, international perspectives and stakeholder network have been incredibly valuable to Air New Zealand and we are fortunate to have had him as a member of our Board," she says.

Key says it was not an easy decision to step away from his Air New Zealand Directorship.

"Air New Zealand is a world class company that all Kiwis can be proud of. The fortunes of the airline and our nation are inextricably linked, so having had the opportunity to support it firstly as Prime Minister and Minister of Tourism and then as a Director has been fantastic. The airline is in great hands under Dame Therese, incoming Chief Executive Greg Foran, a top Executive team and 12,500 staff committed to delivering outstanding uniquely Kiwi experiences every day."

Air New Zealand will advise a replacement Director for Key in due course.

- More to come