Networking giant Cisco could abandon its $3 billion offer for Norwegian video-conference company Tandberg if it does not obtain 90% of the shares, it said in a statement on Tuesday. The company also said it currently holds rights to acquire 9.37% of Tandberg. Cisco's offer on Tandberg was due to expire on Monday, but the company extended the acceptance period until Nov. 18, leaving the terms and conditions unchanged. "Soon after expiration of the extended offer period on 18 November 2009 at 5:30 pm CET (1630 GMT), Cisco will announce whether the 90% condition for the offer has been met," the American firm said Tuesday in a statement sent to the Oslo stock exchange. "If not, Cisco will evaluate whether or not to withdraw the offer," it said, indicating it currently held rights to 10.5 million Tandberg shares. The Tandberg board has unanimously accepted Cisco's offer but it has faced resistance from some shareholders who believe it is too low. The offer, all in cash, is equivalent to 153.50 kroner per share. Tandberg employs 1,500 people worldwide. Copyright Agence France-Presse, 2009