Google Inc received U.S. antitrust approval to buy Motorola Mobility, a deal aimed at building up an arsenal of patents, and an Apple-led consortium also received the go-ahead to purchase a trove of patents from bankrupt Canadian company Nortel Networks, the Justice Department said.

The department also said on Monday that it would not hesitate to take enforcement action to ensure that essential patents — patents needed to ensure that devices sold by different companies are interoperable — were licensed fairly.

Google also announced that the European Commission cleared the $12.5 billion acquisition earlier today.