FRANKFURT (Reuters) - German flag carrier Lufthansa (>> Deutsche Lufthansa) and other parties say they have bid for parts of insolvent Air Berlin (>> Air Berlin Plc) as administrators look for new investors for Germany's second-largest airline.

Most potential investors appear to be mainly interested in the airline's roughly 140 aircraft and its airport landing and take-off slots rather than the whole business.

Friday was the formal deadline for bids. Air Berlin's administrators are to pick buyers for the assets on Sept. 25.

More than 8,000 jobs are at stake.

Following are details:

LUFTHANSA (>> Deutsche Lufthansa)

The German flag carrier said it had made an offer for parts of Air Berlin, declining to provide more detail. A source told Reuters Lufthansa planned to offer a low three-digit million euro sum for up to 90 planes, including Austrian unit Niki's fleet of 21 Airbus A320 and A321 aircraft and 38 crewed planes it already leases from Air Berlin.

EASYJET (>> EasyJet)

The British budget airline, which media reports had said was interested in acquiring up to 40 of Air Berlin's planes, only confirmed that it has bid for parts of the short-haul business.

"The proposal is consistent with easyJet's focused, city-based strategy in Germany," the British company said.

THOMAS COOK'S (>> Thomas Cook Group) CONDOR, NIKI LAUDA

Former Formula One world champion Niki Lauda has told Austrian media he planned a 100-million-euro ($120 million) joint bid with Thomas Cook's German airline Condor for Niki and 17 leased Air Berlin aircraft.

He has proposed that the planes would fly short- and medium-haul leisure routes, filled with Thomas Cook customers.

Thomas Cook has declined to comment.

RYANAIR (>> Ryanair Holdings plc)

The Irish low-cost carrier said in late August it would not bid for any Air Berlin assets, with its Chief Executive Michael O'Leary describing the carve-up process as "a stitch-up".

ZEITFRACHT

German family-owned logistics firm Zeitfracht has offered to buy Air Berlin's cargo marketing platform Leisure Cargo GmbH, its maintenance business and regional unit Luftfahrtgesellschaft Walter GmbH, which operates 20 Bombardier (>> Bombardier, Inc.) aircraft.

It said it expected its proposal would safeguard around 1,000 jobs at Air Berlin. It declined to say how much it had offered to pay.

HANS RUDOLF WOEHRL

The aviation investor has said he had submitted a 500 million euro offer to buy Air Berlin as a whole. He plans to pay an initial 50 million euros right away and the rest in instalments.

In late August, Woehrl said he planned to bid together with partners, although Lufthansa had turned down his offer to team up as bidders. He has proposed keeping Air Berlin intact as a charter airline rather than carving it up.

LINKGLOBAL LOGISTICS

China's LinkGlobal Logistics has expressed interest in parts of Air Berlin but has asked to be given more time, until Sept. 21, to formulate a bid.

UTZ CLAASSEN

Media reports have said Utz Claassen, the former head of utility EnBW (>> Enbw Energie Baden Wuerttemberg AG), was interested in Air Berlin.

German daily Handelsblatt reported on Thursday that he had put up 100 million euros to buy Air Berlin and had pledged an additional 600 million euros in liquidity.

Claassen has so far declined to say whether he was involved, citing confidentiality.

ALEXANDER SKORA

The German businessman told Reuters on Sept. 8 he had decided against a bid for Air Berlin assets.

He had said in early September he planned a bid jointly with unidentified international investors and aimed to keep Air Berlin flying with a limited route network.

(Reporting by Maria Sheahan)