The stake is being sold by the state and four banks, which together hold 99.87% of Adria stock. Non-binding bids are due by 10 September.

The invitation for bids was published in the Financial Times, Wall Street Journal and the trade magazine Flight Global, AUKN said.

The figures suggest the state wants to retain a stake in the airline in line with the government's plans to offload strategic assets while retaining a controlling interest.

AUKN explained that in line with an agreement on the ongoing restructuring at Adria, the signing of a sales contract was envisaged in the first half of 2013, but that the deadline could also be extended.

Adrie Airways said in response that the owners and the company had been looking for a strategic partner for some time and that the invitation, hoping to facilitate additional reactions from the market, was one of the measured planned as part of restructuring.

Adria Airways posted a Q1 net loss of EUR 8m, a figure said by the management to be in line with plans.

The company finished its financial restructuring last year with a successful capital injection in September 2011 and is now undergoing restructuring.

As part of the EUR 50m capital hike, four banks converted EUR 19.7m in claims into stock.

NLB, Abanka, Hypo Alpe Adria and Unicredit banka Slovenije now hold a combined 27.94% of Adria stock.

The company has been struggling for years, during which time it has been courting several strategic partners.

Fellow Star Alliance members Lufthansa and Turkish Airlines have been mentioned in the media as the most likely white knights.