It depends a lot on the organizations. Logically enough, companies with mostly Norwegians on staff are less inclined to hire non-Norwegian speakers, just because it's more hassle to integrate them into the company (switching between speaking Norwegian and English and all that). This is especially true for more mature companies, as they tend to have older employees (who generally have less experience speaking English).
That said, there's a lot of companies that hire foreign talent. Look for younger companies (eg. Opera Software), and companies that have a logical connections to countries abroad (Eg. DNV-GL, GL being German). Startups are especially flexible, (check startupmatcher.com for that kind of jobs in Norway), and the same goes to companies that have offices other places than Norway.