Niki filed for insolvency last week after Germany's Lufthansa (>> Lufthansa Group), which is buying other parts of Air Berlin (>> Air Berlin Plc), scrapped plans to buy Niki, grounding the airline's fleet and stranding thousands of passengers.

"I can confirm that Niki Lauda handed in an offer (for Niki)," she said. "I can't say how much he offered."

Asked whether he made the bid alone or whether he teamed up with another interested party, she said she did not know.

(Reporting by Kirsti Knolle; editing by Francois Murphy)