The U.S. International Trade Commission (ITC) ruled that Motorola’s Droid smartphones don’t violate three Apple patents, “dealing a blow to Apple’s legal offensive against the Android smartphone ecosystem,” reports “CNET” (). The ruling is preliminary and needs to be approved by the ITC’s full six-member commission.

“We are pleased with today‚Äôs favorable outcome for Motorola Mobility,” Scott Offer, senior vice president and general counsel of Motorola Mobility, said in a press release. “Motorola Mobility has worked hard over the years to develop technology and build an industry-leading intellectual property portfolio. We are proud to leverage this broad and deep portfolio to create differentiated innovations that enhance the user experience.”

Apple alleges that Motorola infringes 24 of its patents (21 of them with Android-based phones, the remaining three with set-top boxes and DVRs), while Motorola previously asserted 18 patents against a variety of Apple products (mostly but not exclusively iPhone, iPad and iPod). Litigation between the two companies has taken place in several different federal courts — primarily the Western District of Wisconsin and the Southern District of Florida — as well as before the ITIC.

In November 2010 Apple sued Motorola, alleging that the company’s smartphone lineup and the operating software it uses infringe on the iPhone-maker’s intellectual property. The two lawsuits came after Motorola sued Apple in October 2010 for patent infringement. Motorola claims that Apple’s iPhone, iPad, iPod touch and certain Mac computers infringe Motorola patents.