Apple’s share of Nortel patent purchase: $2.6B

Apple It turns out Apple (s aapl) wasn’t just a participant in the consortium that included Microsoft (s msft), Sony (s sne) and Research in Motion (s rimm) that won the auction for Nortel’s patent portfolio: It contributed more than half of the $4.5 billion purchase price. Mobile patent portfolios that are up for grabs have become strategically important for Apple to defend itself in a variety of patent disputes over mobile devices with Samsung, Nokia (s nok), HTC and others.

From Apple’s 10-Q filed with the SEC Wednesday:

On June 27, 2011, the Company, as part of a consortium, participated in the acquisition of Nortel’s patent portfolio for an overall purchase price of $4.5 billion, of which the Company’s contribution will be approximately $2.6 billion. This asset acquisition is subject to approval by various regulatory agencies.

Google may have lost out (s goog) to the Apple-led consortium on Nortel, but it’s back on the hunt. It’s been reported that both Google and Apple are also interested in scooping up another collection of intellectual property up for sale, that of mobile-phone designer InterDigital.

It’s clear Apple is ready to play defense on its products, as COO Tim Cook warned Tuesday, “We want people to invent their own stuff. We’re going to make sure we defend our portfiolio from everyone.”

But bulking up on Nortel’s patents, and potentially InterDigital’s, shows Apple is prepared to go on the offensive too.

Photo courtesy of Flickr user Robert S. Donovan