* Deadline won't be extended past Thursday
* Cisco may waive 90 pct ownership requirement
* Tandberg shares up 1.9 pct, still below bid price (Adds NEW YORK to dateline, Cisco shares, details)
NEW YORK/OSLO, Dec 2 (Reuters) - Cisco Systems Inc (CSCO.O) said its bid for Tandberg ASA TAA.OL has been accepted by 84 percent of shareholders in the Norwegian videoconferencing company, and gave a one-day ultimatum to those who have not yet tendered their shares.
Most analysts said the 19 billion Norwegian crown ($3.4 billion) deal is likely to go forward, creating an industry leader in videoconferencing, although the acceptance level by Tuesday was slightly lower than the 90 percent originally set as a minimum requirement.
Cisco reiterated on Wednesday that it could waive that 90 percent requirement, although it still sees it as a key threshold. It said it will announce whether it met that 90 percent level after the offer expires on Thursday at 1630 GMT.
"If not, Cisco will determine whether to withdraw the offer or waive this (90 percent) condition," it said in a statement.
Shares in Tandberg rose 2.2 percent to 165 crowns, still a bit below Cisco's 170 crowns-per-share offer. Cisco shares were up 0.1 percent at $23.94.
Cisco ruled out any extensions to the deadline, which was pushed back three times as Cisco struggled to win shareholder approval.
Cisco raised its offer price 10 percent in November after the original offer was rejected by more than 90 percent of Tandberg shareholders, despite support from the videoconferencing company's board and management.
The strong resistance initially triggered some concerns that Cisco might walk away, but most analysts said the deal was too crucial for it to drop.
Cisco Chief Executive John Chambers has said online videoconferencing was a key growth area on the brink of more widespread adoption.
High-quality, real-time videoconferencing can help companies cut travel costs, and Cisco believes it can do more, such as helping businesses like retailers, banks and hospitals launch services from remote locations.
Tandberg is the leading videoconferencing equipment maker, and the company's products fill a crucial gap between Cisco's high-end TelePresence conferencing products and WebEx desktop video service.
Tandberg holds 40 percent of the mid-tier market for videoconferencing, according to Wainhouse Research.
Cisco has been been stepping up deal-making to broaden its product portfolio to provide for all of its customers' IT needs, including networking, security and videoconferencing. In October it also announced plans to buy wireless gear maker Starent Networks Corp (STAR.O) for $2.9 billion.
Acquisitions have helped the company grow its annual revenue to around $40 billion from around $1 billion in 1995, when Chambers became CEO. Originally focused on routers and switches, it now sells software as well as more consumer-related items like cable set-top boxes and mini video cameras.
Analysts have said Cisco's acquisition of Tandberg could trigger more deals in the videoconferencing space.
No other company publicly showed interest in Tandberg, but analysts have said companies like Microsoft Corp (MSFT.O), Hewlett-Packard Co (HPQ.N), International Business Machines Corp (IBM.N) and Avaya Inc [AVXX.UL] could seek to bolster their technology portfolios with more videoconferencing services.
Polycom Inc (PLCM.O), the industry's No. 2 player, is seen as a target, although its CEO told Reuters last month that it was looking to step up partnerships with companies like HP and IBM rather than pursue a buyout. (Reporting by Wojciech Moskwa in Oslo, Ritsuko Ando in New York; editing by David Cowell and Gerald E. McCormick) ((firstname.lastname@example.org; +1 646 223 6084; Reuters Messaging: email@example.com)) ((Multimedia versions of Reuters Top News are now available for: * 3000 Xtra: visit topnews.session.rservices.com
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