Mayor Bloomberg lost a second attempt to save the city millions a year by lowering wages for 3 percent of civil servants, when an appeals court called his move to unilaterally set the pay rate unlawful.

The mayor exceeded his authority by wresting control of the salaries away from City Comptroller John Liu last April, the Appellate Division said in a decision issued yesterday.

The terse ruling said Hizzoner broke the Civil Service Law.

A city Law Department spokeswoman said the mayor would appeal the decision.