Apple Inc. (Nasdaq: AAPL) and Samsung Electronics Co. say they made no progress toward narrowing their dispute over smartphone and computer tablet patents, increasing the chances a jury will decide the matter starting Aug. 21.

The companies said late Friday they weren’t able to narrow the scope of claims at issue in the lawsuit in out-of-court talks.

The judge overseeing the case in federal court in San Jose, California, asked the parties to try to simplify the dispute, while also ordering the chief executives of the two companies to talk one more time before a jury begins deliberating.

“I think it’s too late to hold out much hope that the parties will settle before the jury comes back,” Mark Lemley, a Stanford University law professor, said yesterday by e-mail after the companies’ reported to the court. “When there is a settlement – and there will be – it will be a global deal involving more than just this case.”

Suits over technology patents between the companies are active on four continents. Lemley said the patent portfolios for both sides are too deep and broad not to settle and there’s a risk that both parties could face injunctions blocking the sale of their products. Apple is seeking to make permanent a preliminary ban it won in court in San Jose on U.S. sales of a Samsung tablet, and to extend the ban to Samsung smartphones.

U.S. District Judge Lucy Koh had directed the companies to report no later than Friday on whether “there has been some successful horse trading” to streamline and simplify claims in the case.

Koh said she remained “pathologically optimistic” a settlement could be reached. Barring such an agreement, she said, she hoped to simplify the matter for jurors, who are to begin deliberating Aug. 21.

Joint Statement

“The parties have met and conferred about case narrowing, but have not been able to narrow their cases further,” according to a joint filing signed by attorneys on both sides. The filing didn’t refer to talks between the CEOs, Tim Cook at Apple and his counterpart at Samsung, Kwon Oh Hyun.

Adam Yates, a spokesman for Suwon, South Korea-based Samsung, declined to comment on yesterday’s filing. Kristin Huguet, a spokeswoman for Cupertino, California-based Apple, also declined to comment.

Apple sued Samsung in April 2011, accusing it of copying patented designs for mobile devices, and Samsung countersued. The case is the first to go before a federal jury in a battle for dominance in a smartphone market valued by Bloomberg Industries at $219.1 billion.

The case is Apple Inc. v. Samsung Electronics Co. Ltd., 11- cv-01846, U.S. District Court, Northern District of California (San Jose).