Austrian former racing driver Niki Lauda on Sunday accused German carrier Lufthansa of trying to "destroy" the Niki airline which he founded.

Niki -- formerly a unit of now bankrupt Air Berlin, and most recently operated by Lufthansa -- was grounded last Wednesday after applying to open insolvency proceedings.

The move came after Lufthansa abandoned plans to buy Niki, a holiday airline with 21 aircraft, together with large parts of Air Berlin because of EU competition concerns.

Lauda, 68, a former Formula One champion, had said last week he was potentially interested in again acquiring the airline he sold to Air Berlin in 2011.

But he has now charged that Lufthansa was effectively blocking the sale of Niki because it "wants to destroy" it, in comments to Bild am Sonntag newspaper.