The Supreme Court on Wednesday sided with California-based Life Technologies Corp. in a patent infringement case that limits the international reach of U.S. patent laws.

The justices ruled unanimously that the company's shipment of a single part of a patented invention for assembly in another country did not violate patent laws.

Life Technologies supplied an enzyme used in DNA analysis kits to a plant in London and combined it with several other components to make kits sold worldwide. Wisconsin-based Promega Corp. sued, arguing that the kits infringed a U.S. patent.

A jury awarded $52 million in damages to Promega. A federal judge set aside the verdict and said the law did not cover export of a single component.

The federal appeals specializing in patent cases reversed and reinstated the verdict.

Patent laws are designed to prevent U.S. companies from mostly copying a competitor's invention and simply completing the final phase overseas to skirt the law. A violation occurs when "all or a substantial portion of the components of a patent invention" are supplied from the United States to a foreign location.

Writing for the high court, Justice Sonia Sotomayor said the law addresses only the quantity of components, not the quality. That means the law "does not cover the supply of a single component of a multicomponent invention," Sotomayor said.

Only seven justices took part in the ruling. Chief Justice John Roberts heard arguments in the case, but later withdrew after discovering he owned shares in the parent company of Life Technologies.