Fiat CEO Sergio Marchionne said that the Italian carmaker won't improve its offer for Opel but remains interested in taking over the European unit of General Motors Corp, according to AP. Marchionne told reporters in Venice on Friday that a tentative Opel deal by rival bidders Magna International Inc. and Russia's Sberbank «is not doing too well.» Sberbank warned Friday the deal could still collapse. Marchionne also spoke of Fiat's takeover of Chrysler, which allowed the U.S. automaker to emerge from bankruptcy protection. Marchionne, who also became Chrysler's CEO, said that returning the loans given to the company by the U.S. Treasury is «the key point of our agenda.» He said he believes Chrysler could present its new product range in the next two weeks.