U.S. officials must show greater cooperation and seriousness in the debate about the future of General Motors Corp.'s (GM) Adam Opel GmbH unit, German Economics Minister Karl-Theodor zu Guttenberg said Thursday.

"What happened overnight in part borders on the absurd," he told reporters on his way to a budget committee meeting.

"I would hope for more seriousness and willingness to compromise from the U.S. side," Guttenberg said.

Germany in the early hours of Thursday delayed a decision on providing state-backed bridge financing to Opel because the U.S. parent company has surprisingly come up with new cash demands.

-Von Beate Preuschoff, Dow Jones Newswires, +49 (0)30 - 2888 4122, beate.preuschoff@dowjones.com

(Nina Koeppen contributed to this report)