The U.S. Supreme Court said yesterday that it would hear an appeal by Merck & Co. Inc. seeking to block a shareholders' lawsuit over its withdrawn pain reliever Vioxx.

A federal appeals court ruling in Philadelphia reinstated the class-action securities lawsuit in 2008 after a U.S. district judge in New Jersey dismissed it on grounds that the claims had been filed too late under statutes of limitations.

The Supreme Court agreed to hear arguments during its term that begins in October.

Merck, which employs about 12,000 people in the Philadelphia area, contends that investors waited more than two years to sue after the first warnings that Vioxx might be unsafe.

The investors' suit is unrelated to the $4.85 billion Merck agreed to pay in November 2007 to settle thousands of lawsuits filed by patients and their survivors over Vioxx.

To date, more than 48,000 plaintiffs have filed claims relating to injuries or economic loss under the settlement.