UPDATE 3-Cisco extends offer period for Tandberg bid

* Cisco extends offer until Nov. 18

* Tally not yet disclosed

* Cisco reiterates original terms, calls it 'a fair price' (Adds comments from shareholders, analyst)

By Richard Solem and Ritsuko Ando

OSLO/NEW YORK, Nov 9 (Reuters) - Cisco Systems Inc (CSCO.O) extended on Monday its $3 billion tender offer for Tandberg ASA (TAA.OL) by nine days, after some shareholders of the Norwegian videoconferencing company demanded a higher price.

Cisco, the largest U.S. network equipment maker, said it would extend its offer, originally due to expire on Monday, to Nov. 18, but the terms and conditions of its 153.50 crown-per-share offer would remain unchanged until then.

Analysts said they expect Cisco to sweeten its bid, possibly to around 160 crowns or 170 crowns. Tandberg shares were up 0.53 percent at 151.80 crowns on Monday and Cisco shares were up 0.3 percent at $23.90.

ABG Sundal Collier analyst Hallgeir Hollup said he believes that Tandberg, the world's leader in videoconferencing products, is worth more.

"We also believe that Cisco will hike the bid," he said.