The U.S. Court of Appeals for the Federal Circuit said the judge in a district court in California had erred in deciding that Apple failed to show that it was likely to succeed on the merits and sent the case back to the district count for further review.

The two companies are engaged in a legal battle that includes more than 20 patent-related cases in 10 countries as they jostle for the top spot in the smartphone and tablet markets.

The patent involved in Monday's ruling has to do with the design of Samsung's Galaxy Tab 10.1 tablet. The U.S. District Court for the Northern District of California had found that the design patent could well be challenged as "obvious", which means it should never have been granted. The appeals court disagreed.

The appeals court also ruled that the lower court was right to deny Apple requested preliminary injunctions which would have stopped the sale of Samsung smartphones and tablets based on three other patents.

These three patents include two that have to do with smartphone design and a third related to scrolling.

The patent ruling in Washington is part of a larger legal proceeding in California. Apple sued Samsung in the United States last year, saying the South Korean company's Galaxy line of mobile phones and tablets "slavishly" copies the iPhone and iPad. Samsung then countersued Apple.

In mid-April, Apple and Samsung agreed that their chief executives would participate in settlement talks to try to resolve the dispute, according to an order by U.S. District Judge Lucy Koh.

Representatives for Apple and Samsung could not immediately be reached on Monday.

Apple, maker of the iPad and the iPhone, had asked in July 2011 for the immediate injunction.

One of the three judges hearing the case dissented from part of the majority decision, saying that the finding for Apple in the tablet design patent should not result in a ruling returning the issue to the lower court but that Apple should have been granted its injunction.

Judge Kathleen O'Malley noted that preliminary injunctions were designed to provide a quick fix in the case of patent infringement, while a remand delays giving that relief.

The case in U.S. District Court, Northern District of California is Apple Inc v. Samsung Electronics Co Ltd et al, 11-1846.

The case in the U.S. Court of Appeals for the Federal Circuit is Apple, Inc v. Samsung Electronics Co Ltd et al, 2012-1105

(Reporting by Diane Bartz; Editing by Tim Dobbyn)

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