One of the seven patents at the heart of Apple's $1.05 billion lawsuit against Samsung Electronics has been tentatively rejected by the U.S. Patent and Trademark Office (USPTO), according to documents filed by Samsung with a Californian court late on Monday.

The USPTO made its decision following a request to re-examine the patent, but has yet to make a final ruling on the matter, it said in a letter dated Oct. 15. Samsung told the court the letter was published to the USPTO website Monday.

Apple's "list scrolling and document translation, scaling, and rotation on a touchscreen display" patent describes a way to indicate the end of a scrollable list on a touch-screen device, and is also known as the "overscroll bounce" or "rubber band" patent.

The company has used this patent in various lawsuits against Samsung and other manufacturers of Android devices. In Germany it won a preliminary sales ban on phones and tablets from Motorola Mobility in September when the regional court of Munich ruled the devices infringed on the European equivalent of the same patent.

Earlier this year, Apple convinced a jury in the U.S. District Court of the Northern District of California, San Jose Division, that Samsung devices infringed the overscroll bounce patent, among others. The jury ordered Samsung to pay Apple $1.05 billion in damages.

The USPTO's letter is relevant to Samsung's attempts to block Apple's motion for a permanent injunction and damages enhancement, the company said in a court filing on Monday.

The USPTO found the patent tentatively invalid because there were earlier technologies patented that are similar to Apple's overscroll bounce patent. These earlier patented inventions are known as "prior art."

Apple's overscroll bounce patent was anticipated by a patent invented by Luigi Lira that describes how to control content in a display, the USPTO said in the claim rejections.

The Apple patent was also anticipated by another patented invention describing a "continuous scrolling list with acceleration", the USPTO said.

Samsung has already worked around the overscroll bounce infringement last year. Instead of letting pages scroll past their boundaries and snap back, the company now shows a blue glow at the edge of the screen when a user tries to scroll past the end of a list.

Loek is Amsterdam Correspondent and covers online privacy, intellectual property, open-source and online payment issues for the IDG News Service. Follow him on Twitter at @loekessers or email tips and comments to loek_essers@idg.com