The organisation's annual barometer, released on Wednesday, reported that 58 percent of Norwegians surveyed said they would be unhappy about gaining a Muslim son-in-law or daughter-in-law.
This compared to 32 percent for a Hindu one, 27 percent for Buddhist, 24 percent for a someone of Jewish faith, and just six percent for a Christian.
“There are some pretty scary numbers here. Especially the high levels of skepticism towards Muslims,” Linda Alzaghari, general manager of Minotenk, a think.tank looking at minority groups, told Aftenposten.
Perhaps surprisingly, immigrants in Norway from Muslim countries were less worried about their own children marrying non-Muslims, than the other way around.
Just 15 percent of Norwegians with an Iraqi background, 19 percent of those with a Somali background, and 39 percent of those with a Pakistani background, said they would be worried about one of their children marring a Christian.
The survey found that as many as 60 percent of Norwegians with an immigrant background felt that they faced discrimination in the country, with the percentage rising to close to 75 percent for Somali immigrants.
“There are huge numbers, and we set the frame very wide. This includes those who have lived here a long time. I'm very concerned about it,” Sunniva Ørstavik, Norway's Anti-discrimination ombudsman, told the newspaper. "Many believe that this is a question about bad people, but it isn't. Most of the discrimination takes place because it is you and I who are doing it.”