Fiat SpA (FIATY) will make an offer for General Motors Corp.'s (GM) German unit, Adam Opel AG, by Wednesday, Fiat Chief Executive Sergio Marchionne said Friday.

"We will be able to make the offer by May 20," Marchionne said on the sidelines of a conference in Turin.

The German government has set May 20 as the deadline to submit offers for Opel.

Austrian-Canadian auto parts supplier Magna International Inc. (MGA) has also signaled its interest in GM Europe.

Company Web site: http://www.fiatgroup.it

-By Jennifer Clark and Liam Moloney, Dow Jones Newswires; +39 06 6976 6924; liam.moloney@dowjones.com