Two key regulatory agencies – one in the United States, the other in Europe – have given the go-ahead for Cisco Systems Inc. (CSCO) to continue its $3 billion acquisition of TANDBERG.

The U.S. Department of Justice (DoJ) on Monday said it won’t challenge the videoconferencing deal and the European Commission, which worked on a joint investigation with the DoJ, cleared the transaction.

The DoJ originally had some antitrust concerns but said in a press release that the videoconferencing market continues to evolve and Cisco has promised the European Commission it will provide interoperable systems.

Cisco wants TANDBERG for its telepresence, or face-to-face meetings over high-definition video, expertise. TANDBERG has headquarters in Oslo and New York; Cisco is based in San Jose, Calif. It is the No. 1 provider of telepresence equipment in the world. TANDBERG, meanwhile, is the world’s largest videoconferencing vendor. It reported about $900 million in revenue in 2009 while Cisco boasted about $35 billion in the same time frame.

Cisco’s takeover of TANDBERG was not always assured – shareholders balked for months at the deal’s proposed per-share price, so much that Cisco almost abandoned its bid for TANDBERG.

The Cisco-TANDBERG transaction should be finalized in a couple of weeks.

Shares of Cisco closed .53 percent higher on Tuesday at $26.65.