UPDATE 2-OppenheimerFunds opposes Cisco offer for Tandberg

* OppenheimerFunds represent 5.78 pct of Tandberg shares

* Says Cisco offer undervalues Tandberg's opportunities

* Not part of earlier SEB opposition group

* Cisco reiterates view that offer is fair

* Tandberg shares fall 0.13 pct, Cisco shares up 1.7 pct (Adds Cisco comments)

By Ritsuko Ando

NEW YORK, Nov 4 (Reuters) - Cisco Systems Inc's (CSCO.O: Quote, Profile, Research) $3 billion takeover bid for Norwegian company Tandberg ASA (TAA.OL: Quote, Profile, Research) is facing increased opposition, with investors owning as much as 30 percent of the video conferencing company's shares now demanding more money.

Investment adviser OppenheimerFunds, on behalf of funds and accounts owning a 5.78 percent stake in Tandberg, said on Wednesday that it will not agree to sell their 6.48 million shares to Cisco at the current offer price of 153.50 crowns per share.

OppenheimerFunds said it remains open to better offers from Cisco or other strategic partners.