FRANKFURT (Reuters) - INTRO-Verwaltungs GmbH, the group controlled by airline investor Hans Rudolf Woehrl, has formally indicated its interest in taking over Air Berlin (>> Air Berlin Plc), it said in a statement on Friday.

"The aim of the offer is to preserve Air Berlin as a whole and continue to operate it as an independent airline," INTRO said, adding the offer was backed by partners and financial investors, whom it did not name.

Woehrl made a name for himself in Germany's aviation world when he bought German airline Deutsche BA from British Airways -- now part of IAG (>> International Consolidated Airlines Group) - for 1 euro

(Reporting by Christoph Steitz; Editing by Maria Sheahan)