By Arpan Chaturvedi and Aditya Kalra

NEW DELHI India's aviation authorities have ruled out intervening in a dispute between Akasa Air and its pilots after the budget carrier accused the regulator of inaction, a legal filing shows.

Over 40 of Akasa's 450 pilots quit without serving their notice in recent weeks, and the airline has sued some of them and challenged Indian authorities in court for not acting on its requests to deal with alleged pilot "misconduct". The airline has also warned of a shut down due to the crisis.

India mandates a notice period of 6-12 months for pilots which some pilot organisations are challenging in court. Akasa argues its contractual obligations with pilots remain in force, and is suing the regulator for not intervening in the public interest.

The Directorate General of Civil Aviation (DGCA) and the aviation ministry in a Sept. 22 filing at the Delhi High Court said Akasa's plea should be thrown out as the regulator is unable to interfere in the matter.

The DGCA "does not have any power or delegated authority to interfere in any employment contract," it said.

Akasa, which has previously said it was in discussion with the DGCA, did not respond to a request for comment on the new filing, which has been seen by Reuters.

A DGCA official declined to comment.

Akasa has accused the DGCA of being "unwilling to take any action" which resulted in "significant financial and operational hardship" to the airline

The pilot resignations caused 632 flight cancellations in August, according to Akasa, an estimated 18% of the roughly 3,500 flights the airline usually operates in a month.

The DGCA contested that position in its court filing, saying it "categorically denies" that Akasa "provided any documents or reasons" in respect of cancellation as a result of pilot exits.

Sharing data, it said only 1.17% of Akasa's flights were cancelled in August.

The 6,000 member Federation of Indian Pilots have also responded to Akasa's plea, saying flight cancellation numbers were "unsubstantiated" and that the DGCA can not interfere in the dispute.

"Alleged mass resignation of pilots ... also serves as an indication of employee discontent," the federation said.

(Reporting by Arpan Chaturvedi and Aditya Kalra; Editing by Mike Harrison)