The Wall Street Journal reports that the US Justice Department is investigating the likely bidders for the patent portfolio of Nortel, following concern that the intellectual property could be used to unfairly limit competition. The failed Canadian infrastructure giant is disposing of around 6,000 patents, including assets related to mobile and 4G technologies. Google has previously been named as the “stalking horse” bidder for the assets, with other potential suitors including Apple, Ericsson, RIM, and a patent acquisition firm which represents companies such as Sony, Cisco, Nokia and Samsung.

According to the report, the authorities have not found major competitive issues with Google’s bid, with this company having explicitly stated that it would use the portfolio as a form of defence for its own products and services. There is believed to be greater concern over an Apple deal, due to the fact that this company is already no stranger to patent battles with its rivals – it already has a number of actions open in the mobile space. Nortel’s patent portfolio is worth around US$1 billion, and an auction process is set to take place imminently.