The United States Patent and Trademark Office has set back Apple in its fight with Samsung Electronics over smartphone patents, ruling that a patent that helped Apple win $1.05 billion in damages against Samsung in a jury trial should never have been granted.

The patent office’s action this week was made public by Samsung in a filing Wednesday in U.S. District Court in San Jose, The New York Times reported. In the document, the Korean electronics giant said the ruling should support its petition for a new trial and its challenge to the damages award.

The document lists portions of the patent that were struck down on re-examination, on the basis that prior patents covered the same inventions, The Wall Street Journal reports. The patent office said that for Apple's claims to be valid, they must be considered patentable despite any "prior art patent and printed publication cited." In a detailed report, the agency said they did not qualify.

Apple is expected to appeal the patent office’s ruling, so the patent has not been invalidated yet.

The patent, No. 7,844,915, is one of six that a jury in August found that Samsung had infringed. It covers usability software that distinguishes between single-touch and multi-touch gestures on a smartphone or tablet screen.

It’s widely known as the “pinch to zoom” patent, but the software is narrower in scope. Apple’s legal documents refer to it as controlling a “scroll versus gesture” feature.

Both companies declined to comment on the ruling, the Journal said.

Of the six patents that were the basis of the ruling against Samsung, this is the second that the patent office has concluded, on re-examination, should not have been granted.

In October, the office came to the same conclusion about the patent for Apple’s “rubber-banding” or “bounce” feature, which makes a digital page bounce when a user pulls a finger from the top of the touch screen to the bottom.

If Apple’s appeals fail, the ruling could lead to a new trial or a reduction in the damage award.

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