By Lawrence Hurley

WASHINGTON, May 19 (Reuters) - The U.S. Supreme Court declined on Monday to hear an appeal filed by healthcare company Baxter International Inc over a patent dispute with rival Fresenius Medical Care AG & Co.

The court's action means a July 2013 ruling by the U.S. Court of Appeals for the Federal Circuit remains intact. That ruling threw out a judgment of almost $24 million that Baxter had won over its patent relating to a dialysis machine.

The appeals court nixed the judgment in light of a decision by the U.S. Patent and Trademark Office, which ruled in a separate proceeding that the patent was invalid years after it was issued.

The legal question before the nine justices was whether courts can throw out patent infringement judgments in cases in which the patent office decides during the litigation that the patent is invalid.

Biotechnology and pharmaceutical industry groups urged the court to hear the case, as did medical device manufacturer Medtronic Inc. They said the appeals court ruling creates uncertainty because it encourages dual-track litigation that can extend the time it takes for cases to conclude.

Baxter's patent was challenged by Fresenius in 2003. Baxter counter-sued and ultimately prevailed, winning a 2012 judgment that required Fresenius to pay for infringement.

During the litigation, Fresenius separately asked the patent office to reconsider whether the patent should have been issued, leading to a 2010 decision in the company's favor.

The case is Baxter v. Fresenius, U.S. Supreme Court, No. 13-1071.

(Editing by Howard Goller and Bernadette Baum)