UPDATE 1-Abengoa's U.S. unit, holdout creditor spar over bankruptcy plan

WILMINGTON, Del./CHICAGO, Dec 6 (Reuters) - A U.S. subsidiary of Spanish renewable energy firm Abengoa SA pressed a judge on Tuesday to approve its plan to exit bankruptcy over objections from a holdout creditor, who said the plan violated U.S. law by favoring the company's foreign parent.