RHJ International, a bidder for carmaker Opel, is not ruling out selling Opel back to U.S. parent General Motors after returning it to health, RHJ's chief executive told a German newspaper on Sunday.

Let us be pragmatic. It won't work without General Motors, the CEO of the Belgian private-equity firm, Leonhard Fischer, told Frankfurter Allgemeine Sonntagszeitung.

The newspaper said Fischer was explicitly not ruling out the option of selling Opel, based mostly in Germany, to GM after RHJ had completed its restructuring of the ailing carmaker.

RHJ and Canada's Magna submitted bids to acquire Opel on July 20.

German Chancellor Angela Merkel has said Magna was Germany's preferred partner for Opel. (Reporting by Marilyn Gerlach, editing by Will Waterman)