The Austrian group cited the offer's valuation of 34 euros per share, deeming it too low, as well as a potential delisting from the Vienna Stock Exchange as contrary to the interests of the firm.

Furthermore, Austria's economy ministry sent its conditions to the bidder, insisting that IFM could not nominate more than two candidates for elections to the supervisory board and may not propose any changes to the articles of association, IFM said earlier on Tuesday.

There would be reporting obligations to the ministry, in particular regarding compliance with the conditions, it added.

IFM holds 40% of Flughafen Wien's stock. The city of Vienna and the region of Lower Austria each hold 20%.

Flughafen Wien's share closed at 33.95 euros on Monday.

(Reporting by Tristan Chabba in GdanskEditing by Paul Carrel)