Tech giants continued attempts to shore up their patent portfolios continued on Wednesday, with InterDigital being targeted by Apple, Nokia and Qualcomm.

Bidders have been eager to get their hands on InterDigital”s 8,800 patents — including crucial 3G and 4G/LTE patents to strengthen operating software for smartphones.

Key potential bidder Google, who earlier this week acquired Motorola Mobility for $12.5 billion, has not formally withdrawn from the auction but it is unclear whether they will bid for the company.

In related news the head of Google’s rival Nokia warned that phone makers depending on Android software should worry about the Web search leader’s deal to buy Motorola Mobility.

Analyst concern about whether Motorola will get preferential treatment over rivals Samsung and HTC are justified said Nokia Chief Executive Stephen Elop.