Lauda bids to buy back Austria airline Niki

* Lauda has handed in offer - Lauda spokeswoman

* Ryanair, Zeitfracht/Nayak won't bid for Niki

* Proposal to be presented to creditors on Friday

* Administrator aims for sale by year-end (Adds report from Bild/Berliner Zeitung)

BERLIN/VIENNA, Dec (Shanghai: 600875.SS - news) 21 (Reuters) - Former motor racing world champion Niki Lauda has offered to buy Austrian holiday airline Niki, a company he founded, but Ireland (Other OTC: IRLD - news) 's Ryanair has pulled out of the bidding.

A consortium of family-owned logistics firm Zeitfracht and maintenance group Nayak also decided against an offer, increasing Lauda's chances of repurchasing an airline he set up in 2003.

"I can confirm that Niki Lauda handed in an offer (for Niki)," his spokeswoman said, declining to say how much he offered or whether he had teamed up with anyone.

Niki, part of collapsed Air Berlin (LSE: 0GPE.L - news) , filed for insolvency last week after Germany's Lufthansa (Xetra: LHAB.DE - news) backed out of a deal due to competition concerns, grounding the airline's fleet and stranding thousands of passengers.

Niki's administrators, who had asked for binding offers by Thursday, have been racing to find an alternative buyer for its assets before it loses its takeoff and landing slots, its most attractive asset.

German newspapers Bild and Berliner Zeitung said tour operator Thomas Cook (Frankfurt: A0MR3W - news) , British airways parent IAG , and Tuifly, the airline of tour operator TUI (LSE: 0NLA.L - news) , also submitted bids, citing a person familiar with the offers.

Other interested parties include Swiss carrier PrivatAir.

Thomas Cook and IAG declined to comment. A spokesman for TUI (Swiss: TUI1.SW - news) said that Tuifly was interested in any runway slots that might become available but declined to comment further.

SWIFT DEAL SOUGHT

Administrator Lucas Floether told Reuters he aimed to strike a deal by the end of the year.

"We will assess the offers ... and present them to the creditors on Friday. There a decision will be made with which bidders negotiations will continue," he said.

Any buyer will have to give Niki a loan, in addition to the purchase price, so it does not collapse before the acquisition closes, administrator Floether said, without saying how much money he expected Niki to fetch.

Ryanair decided not to bid because there was "insufficient clarity about Lufthansa aircraft leases to Niki which we couldn't resolve in time," the Irish carrier said in an emailed statement.

Lufthansa, which still plans to buy other parts of Air Berlin, has already arranged with lessors to take on some of the Niki planes, which has drawn criticism from Lauda.

Lufthansa has said that it will honour conditions set out by the European Commission under which it must transfer planes to any alternative Niki purchaser.

A spokesman for Zeitfracht said that while it wasn't bidding, it still wanted to cooperate with whoever ends up buying the unit of collapsed Air Berlin. (Reporting by Kirsti Knolle, Victoria Bryan, Klaus Lauer and Ilona Wissenbach; Additional reporting by Christoph Steitz; Editing by Maria Sheahan/Keith Weir/David Evans)