German investor Heinz Hermann Thiele sharply criticised a 9-billion-euro (8.06 billion pounds) bailout deal for carrier Lufthansa, saying he had raised his stake in the group to more than 15% and hoped alternative options could be explored.

In an interview with German newspaper Frankfurter Allgemeine Zeitung (FAZ), Thiele, Lufthansa's top shareholder, said he was not satisfied with the deal giving the German government a 20% in Lufthansa as well as two seats on its supervisory board.

Lufthansa, led by Chief Executive Carsten Spohr, earlier this month agreed to the terms.

"I appreciate Mr Spohr, but I'm not satisfied by his statement that everything was examined and that some ideas could not have been implemented. I believe that negotiations could have been more intense," Thiele was quoted by FAZ as saying.

He declined to say whether he would vote against the deal at Lufthansa's extraordinary general meeting, scheduled for June 25, where investors will be asked to approve the agreement.

Thiele said an indirect state participation via lender KfW [KFW.UL] could be an alternative to an outright government stake.

"My goal is to create an understanding that there could actually be an alternative - even though this is being denied by management. It is possible to hold talks and clarify where there is leeway."

(Reporting by Christoph Steitz; Editing by Mark Heinrich)