Top budget airline AirAsia has had its right-to-fly extended by six months rather than the standard two years after an audit by Malaysian regulators found "some issues", an official said today.

The government official said the department of civil aviation had decided to extend the low-cost carrier's air operator's certificate until March 31 next year, at which point it will need to reapply.

The certificates, which allow carriers to use aircraft for commercial purposes, are usually granted for two years.

"The department already audited AirAsia, and they only approved six months for AirAsia," the official told AFP.

"AirAsia needs to apply again for renewal... next year," he added.

The official said the carrier, Asia's largest low-cost carrier by fleet size, faced "some issues... that have been found" but did not elaborate further.

A local daily reported today, quoting sources, that AirAsia had failed to meet regulatory standards.

The daily said an audit showed "shortcomings in AirAsia's flight operations procedures and practices, including flawed communications between flight operations and pilots, an outdated manual and flight operations not in keeping with the manual".

It also reported that AirAsia's head of flight operations had been removed from the post and replaced.

AirAsia did not immediately return requests for comment.

An aviation analyst told AFP he could not verify the report but said if it was true AirAsia would do "whatever it takes" to get another certificate next year.

"I think this will just be a warning... They have a very clean track record" in terms of safety, he added.

Rapidly expanding AirAsia has become one of the airline industry's biggest success stories, rivaling national carrier Malaysia Airlines, which has been struggling to get out of the red.

Head Tan Sri Tony Fernandes acquired the then-failing airline a decade ago. He has set up subsidiary budget carriers in Indonesia, the Philippines, Thailand and Japan.

The discount carrier has a fleet of 112 A320s and is expecting 266 more aircraft to be delivered up to 2026.

The airline, one of the biggest customers for European aircraft maker Airbus, has said it is in discussions to buy an additional 100 aircraft.

AirAsia's shares closed down 0.70 per cent at RM2.83 today. - AFP