The building owners filed suit in August 2001 on behalf of current or former owners of properties containing asbestos flooring, which Armstrong made until 1982.

They alleged that the old floors posed a health risk and therefore damaged the value of their properties, which Armstrong denied.

Judge Randall J. Newsome declined to certify the building owners designated by the suit to act on behalf of the owners and threw out the suit.

"It would be difficult to concoct a group of class representatives with greater conflicts, or less incentive, to vigorously represent the class," Newsome ruled this week.

The lawsuit sought to have Armstrong pay for a national advertising campaign alerting property owners to the hazards of asbestos flooring and helping them identify it. Armstrong also would have had to establish testing centers where property owners could send samples of their flooring to be checked for asbestos.