Shares in Norwegian video conference systems maker Tandberg (TAA.OL) drop 3.9 percent on a rising Oslo bourse after U.S. peer Polycom (PLCM.O) posted lower quarterly profits and forecast lower-than-expected revenue for the second quarter.

Shares in Polycom were down more than 7 percent in trading after the bell.

Pareto Securities cuts its recommendation on Tandberg to "hold" from "buy". The stock hit a seven-month high on Wednesday.

"We expect Tandberg to have gained market share in the quarter, but do believe the challenging macro (economic environment) will hit other video-conferencing players as well," the brokerage says in a note to clients.

Arctic Securities cut on Friday its rating on Norwegian video conferencing systems maker Tandberg to 'sell' from 'buy' following Tandberg's first-quarter report on Thursday, the brokerage told Reuters.

'Tandberg has been seen as a counter-cyclical company and has for several quarters delivered fantastic results and high growth. Now the effects (of the financial crisis) have caught up with Tandberg,' analyst Martin Hoff at Arctic Securities said.

[via Forbes and Reuters]