FRANKFURT (Reuters) - German airline Lufthansa LHAG.DE aims to take on around a dozen of Air Berlin's AB1.DE 17 long-haul aircraft and their transatlantic routes in a carve-up of the insolvent carrier, a person familiar with the matter told Reuters on Tuesday.

FILE PHOTO:German carrier Air Berlin's aircrafts are pictured at Tegel airport in Berlin, Germany, September 29, 2016. REUTERS/Axel Schmidt/File Photo

Air Berlin, Germany’s second-largest airline, filed for bankruptcy protection this month after shareholder Etihad Airways withdrew funding following years of losses.

At least half a dozen bidders for Air Berlin’s assets are now racing to submit offers by a mid-September deadline, with around 140 leased aircraft and valuable take-off and landing slots in Germany up for grabs.

Lufthansa, which currently does not offer long-haul flights from Berlin, is especially interested in the carrier’s routes to U.S. cities including New York, the source said on Tuesday.

Lufthansa, which has the German government’s backing to take over major parts of Air Berlin, could acquire as many as 90 of its planes, including 38 aircraft it is already leasing from the airline and its leisure unit Niki, another source told Reuters this month.

Such a deal, seen valued in the low hundreds of millions of euros, could see up to 3,000 of Air Berlin’s workers move to Lufthansa, the person familiar with the matter said on Tuesday.

Britain's easyJet EZJ.L and Thomas Cook's TCG.L Condor could split the rest of the fleet between them, media reports have said, with easyJet interested in up to 40 planes and Condor a double-figure number.

Ryanair RYA.I CEO Michael O'Leary has meanwhile complained that the Air Berlin insolvency process was a "stitch-up" to help strengthen Lufthansa. He is due to speak to journalists in Berlin on Wednesday.

LEGAL MOVE

Former motor racing driver Niki Lauda has expressed interest in buying back leisure unit Niki, which he founded, and aviation investor Hans Rudolf Woehrl wants all of Air Berlin.

Labour bosses bemoaned that all the bidders were so far focusing on Air Berlin’s aircraft, routes and landing slots and neglecting the 2,800 workers at its maintenance unit and in administration. Air Berlin has a total of 8,000 workers.

In that respect, a takeover by one investor would be better, union leader Christine Behle said on Tuesday, although she added it was more likely that Air Berlin would be carved up.

The carrier is being kept in the air thanks to a 150 million euro ($177 million) government loan, which it has said would last for up to three months.

Rival German airline Germania on Tuesday asked a Berlin court to block the bridge loan until the European Commission had given its go-ahead for such state aid.

Behle said without the bridge loan, passengers would be stranded and jobs endangered.

However, the German economy ministry said the legal move would not stop disbursement of the funds, adding Berlin expected the European Commission to approve the loan. A Commission spokeswoman was also optimistic for an approval.

According to Air Berlin, bidders have until Sept. 15 to submit their offers.

Air Berlin said on Tuesday it was bringing forward by a month to Oct. 1 the planned cancellation of its services from Berlin to Los Angeles and San Francisco and from Duesseldorf to Boston. It will still fly from Berlin to Miami and New York.