Not many people outside Norway speak Norwegian and, as a result, Norwegians have become extremely proficient foreign language speakers. It is not at all uncommon for your Norwegian counterpart to speak three or four foreign languages and English language levels are almost universally good.
Plain speaking is prized and the more diplomatic approach to communication which can be found in many of the Asian countries, (as well as the UK), can be viewed as evasiveness or even as dishonesty. If you want to convince a Norwegian, tell him the facts in a straightforward and direct manner. Norwegians will tell you they disagree when they do - and they expect the same courtesy from you.
Try not to 'oversell' a product or an idea. Be objective in your discussions and do not be afraid to point out any weakness in your argument - this level of honesty will bring you respect and is much more likely to reap rewards than a more self-promotional approach.
Silence is golden throughout most of Scandinavia. More is less,so if you don't have anything to say,don't speak! Do not feel the need to fill any silence with conversation. Silence is often used as thinking time and the prelude to what will be said next.
Body language is quite minimal but do not take the lack of any overt signs of interest as disinterest. Reserve is a highly prized characteristic and it would be foolish to interpret lack of emotion as a sign of boredom or as lack of attention.