OSLO — For a people whose deep national pride is in bestowing the Nobel Peace Prize, Norwegians are developing a reputation for throwing some sharp elbows.

And they are doing so in an unexpected way: by pulling investments out of Wal-Mart and other big companies like Boeing and Lockheed Martin for what they say are ethical failings.

Norway has amassed a fortune of more than $300 billion over the last decade, thanks to its profits from oil exports. Yet few countries are more ambivalent about their vast wealth than this modest, socially conscious society of less than five million people.

So rather than managing their monstrous nest egg simply for the best returns, the reluctant billionaires of Norway are using the money to advance an ambitious ethical code they established in 2004 for their oil reserve, known as the Government Pension Fund.