Google and Motorola Mobility have been ordered to hand over information to Apple about the development of the Android operating system.

A Chicago judge yesterday sided with Apple, who said the information is "highly relevant" to its patent suit against the Illinois-based smartphone maker.

Judge Richard Posner also ruled that Google and Motorola Mobility must disclose facts about their $12.5 billion merger, which is still pending.

Motorola had argued Google was a "non-party" to the case because the acquisition had not closed and should not be forced to produce documents about Android. Motorola has filed a countersuit against Apple in the case.

The trial for the patent dispute is set to begin this summer, according to Bloomberg.

Apple is has filed a multitude of patent complaints against manufacturers of Android-based smartphones, which it says are using its intellectual property without permission. Apple's high-profile multinational fight against Samsung has yet to result in a definitive winner, with rulings issued in favor of both sides.

Microsoft also has aggressively targeted Android manufacturers, signing a number to licensing arrangements for its patents.

Motorola Mobility has so far refused to pay Microsoft fees for its use of the Android platform, and the companies are still waiting a final decision on an important case before the U.S. International Trade Commission, which has the power to block companies from selling and importing products found to violate patents.