Mark McNabb, vice president of General Motors Corp.’s Cadillac Div., will leave the auto maker, a spokesman confirms.

McNabb joined GM a little more than a year ago from Nissan North America Inc. He will exit the auto maker June 1 to pursue other opportunities, the spokesman says.

Replacing McNabb on an interim basis is Stephen J. Hill, who also will continue in his position as general sales manager of GM’s premium channel (Cadillac, Hummer, Saab). There’s no timetable for naming a permanent replacement, the auto maker says.

Meanwhile, GM reportedly has narrowed the list of candidates to purchase its Saturn operation to two, Penske Automotive Group Inc. and private-equity firm Black Oak Partners LLC, Bloomberg reports.

The news agency says a third bidder still could emerge and that Magna International Inc. could build vehicles for Saturn in a partnership with another bidder. Magna has denied it is interested in purchasing a stake in Saturn, however.

Both Renault SA and Mitsubishi Motors Corp. reportedly have expressed interest in supplying cars for Saturn.

Separately, GM is expected to get E750 million ($1.0 billion) in a bridge loan from the German government to help sustain its Adam Opel GmbH operations while it continues to look for a buyer. Three companies have expressed interest in Opel, including Fiat Auto Group, Magna and RHJ International SA, a division of private-equity firm Ripplewood Holdings LLC.

GM will get additional financial help from the U.S. government, which reportedly is set to pour another $7 billion into GMAC LLC, the finance arm the auto maker owns with Cerberus Capital Management LP.