FRANKFURT (Reuters) - Former motor racing champion Niki Lauda's winning bid for insolvent Austrian airline Niki beat that of British Airways owner IAG (>> International Consolidated Airlines Group) by 4 million euros ($5 million), a German newspaper reported on Sunday.

Lauda offered 30.3 million euros for the carrier, plus a 16.5 million euros liquidity injection, German weekly Bild am Sonntag said, citing sources close to the negotiations.

The sale to Lauda, announced on Monday, undid an agreed deal with IAG after two courts ruled that the insolvency proceedings had to move to Austria from Germany. Lauda has not said so far how much he is paying for Niki.

Bild am Sonntag said he had already transferred around 12 million of the purchase price.

A spokeswoman for Lauda declined to comment.

The paper also said that around half of what Lauda is paying will go towards paying back a government loan that Niki parent Air Berlin (>> Air Berlin Plc) received when it collapsed in August.

Germany's Economy Ministry declined to comment on the report.

(Reporting by Maria Sheahan. Additional reporting by Brenna Hughes Neghaiwi in Zurich and Thomas Escritt in Berlin. Editing by Jane Merriman)