An agreed sale of Niki to British Airways owner IAG (>> International Consolidated Airlines Group), brokered by Niki's German administrator, was thrown into doubt last week by two court rulings saying Austria was the relevant jurisdiction for the insolvency proceedings.

This paved the way for former Formula One world champion Lauda to bid again for the airline he founded in 2003, but which most recently was part of failed airline Air Berlin (>> Air Berlin Plc), itself bought by Lufthansa (>> Lufthansa Group).

The deadline for new offers to be submitted to Niki's Austrian administrator, who is cooperating with her German counterpart, is Friday and both IAG and Lauda have said they will bid again.

Ryanair (>> Ryanair Holdings plc) has also expressed an interest. Niki's landing and take-off rights - or slots which airlines that have been grounded too long can lose - are its most attractive assets, along with its workers.

In his letter to Niki employees - of which there were around 1,000 in December, although some have quit since - Lauda said he could finance his bid without any problems, but did not give figures or details.

A spokeswoman declined to comment further. IAG has offered jobs for 740 employees, 20 million euros ($24.5 million) and an additional 16.5 million euros in liquidity for Niki.

"My Laudamotion GmbH has an AOC (certificate to allow commercial flight operations) and an operating permit and can take over (Niki's) slots immediately," Lauda said in his letter.

"All Niki employees will get a job offer ... Not only will flight operations be taken over but also administration and technology (operations)."

($1 = 0.8152 euros)

(Reporting by Shadia Nasralla; Editing by Mark Potter)