The boss of Qantas' international operations has resigned after only a year and a half in the senior position.

The airline said on Thursday morning that Alison Webster's last day as chief executive of Qantas International would be April 24. No explanation for the departure was given.

Ms Webster joined Qantas in 2004, and was head of cabin crew and ran its freight division before taking over international operations from Gareth Evans, who became CEO of Qantas' budget arm Jetstar.

The 51-year-old started her aviation career with British Airways in 1989, and later worked in senior roles at Heathrow airport.

Qantas said Narendra Kumar, a former CFO of Qantas International, would take over as acting CEO while the airline looks for a permanent replacement.

Mr Kumer was "currently overseeing planning for key changes to the airline’s long-haul fleet", Qantas said.

More to come