WASHINGTON -- The Supreme Court turned away a class action lawsuit against cable provider Comcast Corp., in a decision that could make it harder to file those types of lawsuits in federal court.

The high court on Wednesday overturned a lower court decision to certify as a class customers who say the company's monopoly in parts of the Philadelphia area allowed it to raise prices unfairly.

Justice Antonin Scalia said in a 5-4 decision the customers need to be able to show that they can tie a single theory of how they were harmed to a specific calculation of damages for class certification. The Comcast subscribers had a model that would have shown damages, but it showed $875 million of damages done under four different theories.

Only one of their theories was accepted by the lower courts, so there is no showing of how much in damages was attributable to that theory, Scalia said.

"It is clear that, under the proper standard for evaluating certification, respondents' model falls far short of establishing that damages are capable of measurement on a classwide basis," said Scalia, who was joined in his opinion by Chief Justice John Roberts, and Justices Anthony Kennedy, Clarence Thomas and Samuel Alito.

Some say this will make it more difficult to file class actions.

The court's decision "reinforces that courts can't rubber stamp proposed class actions without first taking a hard look at the plaintiffs' claims," said Kate Todd, a lawyer at the National Chamber Litigation Center. "The reality is that frivolous class actions impose unjustified litigation and settlement costs on businesses that are passed on to consumers. Today's decision is a victory in the effort to curb class action abuse."