Microsoft objected to the sale of bankrupt Nortel Networks patents on Monday.

The software giant claims Google should not be able to purchase thousands of Nortel patents under the current sale terms. Reuters news agency reports that Microsoft filed documents with a Delaware bankruptcy court on Monday. Microsoft says it has a “worldwide, royalty-free license to all of Nortel’s patents” after securing a deal with the company in 2006.

Google is bidding $900 million for more than 6,000 patents. Microsoft didn’t need to bid for the patents thank to its patent cross-license deal signed with Nortel in 2006. Microsoft’s objection was clear in the court documents submitted on Monday. The proposed sale “would result in considerable disruption in the development and enhancement of various existing technologies and give the prospective purchaser an unfair competitive advantage,” said Microsoft, reports Bloomberg.

Microsoft issued the following statement on Monday:

“Microsoft wants any new owners of the Nortel patents to be subject to Nortel’s existing commitments to Standards Setting Organizations and to Microsoft. By making this filing, Microsoft preserves its ability to raise this issue with the bankruptcy court in the event the final buyer of the Nortel assets seeks to disclaim any of these commitments.”

Nortel filed for bankruptcy in January 2009. The Canadian phone-equipment maker agreed to sell the patents to Google for $900 unless a higher bid is accepted in an auction later this month. Nortel’s patents include rights to control and license technologies like wireless-video. Nortel also held an auction for 666,624 IPv4 addresses recently. Microsoft submitted the highest bid valued at $7.5 million. The figure works out to $11.25 per IP address.