Cisco raises bid for Tandberg

US computer group Cisco has raised its bid for Norwegian video conferencing company Tandberg to $3.4bn (2bn).

The company's last bid of $3bn, made on 1 October, did not find favour with Tandberg's shareholders.

Cisco said its new bid already had the backing of 40% of shareholders, and analysts said it was likely to succeed.

Cisco added it would not return with a higher offer if the bid failed, and would look elsewhere to expand in the video communication market.

Cisco, the world's largest maker of network equipment, has said its expertise would improve Tandberg's service and boost its popularity.