WASHINGTON (AP) _ The Supreme Court abandoned plans Tuesday to rule on a major reverse discrimination case, concluding the case involving a white-owned contractor wasn't a good vehicle for deciding whether federal affirmative action rules amount to reverse discrimination.

The court's action, taken in a unanimous, unsigned ruling, is an anticlimactic end to what had been billed as a blockbuster affirmative action case. Opponents of racial preferences had hoped the court would use the 11-year fight over government highway contracts to effectively declare federal affirmative action programs unconstitutional.

The case, Adarand Constructors Inc. v. Mineta, had developed procedural problems that several justices suggested last month were too messy to fix.

The case began as a new test of whether the government can offer incentives to minorities or others traditionally at a disadvantage in the business world without unconstitutionally harming white-owned businesses.

Opponents of affirmative action, including many conservatives close to the Bush administration, hoped the court would use the case to effectively eliminate affirmative action programs in the federal government. The court flirted with that dramatic step in a 1995 case involving the same small, white-owned Colorado construction firm at the heart of the case decided Tuesday.

Supporters of the practice feared that at the least, another ruling in the Adarand dispute would make affirmative action even more constitutionally suspect than it is now.

The court agreed to hear the latest Adarand case in March. But at oral arguments Oct. 31, it was apparent that the two sides could no longer agree what they are fighting about, or whether there was even a case at all.

Much of the hourlong session focused on whether the Adarand construction company even has proper legal footing to claim discrimination. The justices appeared frustrated, and several asked lawyers for both sides what the court should do with the muddle.

Justice Stephen Breyer suggested one option was just what the court did Tuesday.

The court's short ruling laid out the procedural problems with the case, and concluded that the justices could not step in to set things right. That said, the court concluded it could not address the merits of Adarand's affirmative action complaint.