German Economy Minister Karl-Theodor zu Guttenberg said on Saturday Austrian-Canadian auto parts supplier Magna is a potential investor in General Motors' struggling German unit Opel.

Magna is a potential interested partner, he told Der Spiegel news magazine, in comments released on Saturday ahead of the magazine's publication. We'll obviously examine their possible entry quite seriously.

The Economy Ministry said Guttenberg would take a closer look at Magna's possible interest at the start of next week. A spokesman said there were several other potential investors interested in Opel with whom the ministry would be talking.

GM must sell a significant stake in Opel to convince German politicians to use taxpayers money for 3.3 billion euros ($4.30 billion) in loan guarantees.

GM Chief Executive Fritz Henderson said last week the carmaker had reached out to more than six potential buyers, many of whom were financial investors.

But private equity firms are giving Opel the cold shoulder, leaving sovereign wealth funds from the Gulf or Asia as the most interested private investors, managers at buyout firms have told Reuters.

Fiat SpA has emerged as another possible suitor for Opel, whose future depends on GM and the German government finding an investor. But Fiat has sought to play down expectations of an imminent offer for Opel.

Opel Chief Executive Hans Demant said he was pleased about the interest from investors in the troubled car maker and pledged to keep these parties informed of the situation.

(Writing by Erik Kirschbaum, editing by Mike Peacock)