Apple, Inc. (AAPL) has put Taiwan's HTC Corp. (SEO:066570) in a very bad spot.  The larger, more profitable gadget maker has hit HTC with a series of lawsuits worldwide, and recent scored a favorable preliminary ruling, which could lead to a complete ban on HTC handsets in the U.S.

But HTC appears to have some leverage, now.  In an unsealed ruling dating back to July 1, it has been declared that Apple infringed on intellectual property of recent HTC acquisition S3 Graphics.

The IP in question covers image compression techniques in software and hardware.  The U.S. International Trade Commission Judge James Gildea ruled that while Apple's popular iPad, iPhone, and iPod lines of mobile gadgets are not in violation of the IP, some of Apple's Mac OS X computers are.  

As NVIDIA Corp. (NVDA) is a licensee, units with its GPUs are not in violation.  However, models with graphics by Advanced Micro Devices, Inc. (AMD) or integrated graphics from Intel Corp.'s (INTC) (such as the newly refreshed MacBook Air lineup) are in violation.

The ruling thus clears the way for a partial ban on the import of Macs.  As virtually all Macs are manufactured outside the U.S. (mostly in Asia), this would be a major blow to Apple's booming computer lineup, which posted in $17.5B USD computer sales last year.

The judge also ruled that two of S3's patents in the case were invalid, and that some of the minor claims within the two valid patents were invalid.

While the ruling was "unsealed" (made official), it has not yet been made available to the public as the companies are reportedly quibbling about what constitutes redaction-worthy confidential information in the document. Bloomberg reported on the release, based on early information.

The ruling now goes before a full six judge ITC panel for confirmation.

While a ruling which found Apple's iPad and iPhone -- which accounted for 46 percent of its revenues last year -- would have been even better, the victory gives HTC substantial leverage to broker a cross-licensing agreement, which could save HTC from a similar import ban on its smart phones.

Meanwhile, Apple filed two weeks ago, on July 15, a new ITC complaint against the HTC Flyer tablet, which it says infringes on several of its patents.  Of course, if the companies can come to terms, HTC's tablet lineup would, in theory, be covered under a cross-licensing agreement, as well.

If the S3 IP can save HTC from Apple's litigious wrath, that $300M USD acquisition, which was blasted by investors, could just turn out to be a great deal.