The US International Trade Commission (ITC) issued rulings this week in separate patent-infringement cases against Apple and Microsoft and found that both companies have violated Motorola Mobility patents in some way. However, a US district court judge previously ruled that Motorola wouldn't be able to halt the sale of Microsoft’s infringing products, regardless of the outcome.

The ITC found that Microsoft infringed against four of the five patents that Motorola Mobility claimed were in violation. That’s not particularly surprising, however, since the patents in question involve industry standards for commonly used technologies such as Wi-Fi and video playback. Motorola had previously requested an injunction against Microsoft, which could have halted the sales of Windows and Xbox, two of the software giant’s core products.

Two weeks ago, however, a US district judge sided with Microsoft in a complaint involving Motorola’s injunction request. And that ruling means that even if the ITC does grant Motorola the injunction, it can’t take effect until the US district court separately rules whether Motorola has violated the fair, reasonable, and nondiscriminatory (FRAND) licensing regulations that apply to standard essential patents.

Motorola, of course, was pleased with the ITC ruling, although the ruling won’t be certified until a six-member ITC commission reviews it in August.

“Microsoft continues to infringe Motorola Mobility’s patent portfolio, and we remain confident in our position,” Motorola spokesperson Becki Leonard said. “This case was filed in response to Microsoft’s litigate-first patent attack strategy, and we look forward to the full commission’s ruling in August.”

Meanwhile, in a similar case against Apple, the consumer electronics giant was found to have infringed on two of six patents that Motorola Mobility claimed were in violation. In that case, Motorola is likewise seeking an injunction that would halt the sale of Apple’s iPhone and iPad products. And as with the Microsoft case, it too revolves around FRAND licensing—in this case, for 3G wireless technologies.

As in the Microsoft case, Motorola must await an August commission review before a possible injunction will occur. Apple had separately fought to block the sale of Motorola Mobility products in October 2010 but lost that case. It is currently in appeal, and Motorola’s current case against Apple dates back to that time.

Not coincidentally, the European Union (EU) is separately investigating complaints by both Apple and Microsoft that Motorola Mobility is illegally wielding its standard essential patents to harm competition.

Motorola Mobility is still waiting on Google to complete its $12.5 billion acquisition of the company. But these court actions in the United States and Europe could cause problems for the antitrust regulators that previously approved the sale. When the EU approved the Google purchase of Motorola in February, for example, it specifically called out its “worry” that Google would “abuse” the many patents it would acquire as part of the Motorola Mobility purchase. If Apple and Microsoft are to be believed, that abuse is already happening.