(Reuters) -Australia's competition watchdog said on Friday it had given Qatar Airways interim approval to take a 25% stake in Virgin Australia [IPO-VIR.AX] and for the duo to start selling return flights between the countries starting in June of next year.

The tie-up will give Qatar, which plans to buy the stake from U.S. private equity firm Bain Capital, a backdoor channel to increase flights into Australia after being denied by the Albanese government last year. The government still needs to sign off on the latest proposal.

Qantas Airways had been fighting to keep Qatar away from Australia and had gotten assistance from a Labor government. The denial last year raised questions about the government's relationship with Qantas, which has a partnership with Dubai-based Emirates, a rival of Qatar Airways.

Qatar Airways and Virgin Australia can start marketing and selling 28 weekly scheduled return flights between Doha and Brisbane, Melbourne and Sydney, in June, the Australian Competition and Consumer Commission (ACCC) said in a statement.

Flights from Perth are scheduled to start in November.

The ACCC's interim authorisation ensures that customers who have pre-booked these flights would be protected, even if the final regulatory approval is not granted.

Virgin Australia will use Qatar Airways' craft and crew to operate the service under a wet-lease arrangement.

Virgin Australia, Qantas and Qatar Airways did not immediately respond to a Reuters' request for comment.