Norwegians have eaten up the country's entire stockpile of butter, partly as the result of a "low-carb" diet sweeping the Nordic nation which emphasizes a higher intake of fats.

"Sales all of a sudden just soared, 20 per cent in October then 30 per cent in November," saidLars Galtung, the head of communications at TINE, the country's biggest farmer-owned cooperative.

A wet summer which reduced the quality of animal feed and cut milk output by 25 million litres had already limited supplies and the shortage has led some pundits to suggest the world's eighth-largest oil exporter offer some of its plentiful fuel supply in exchange for butter.

"Norwegians are not afraid of natural fats, they love their butter and cream," Galtung told Reuters.

Butter is now selling on Norway's top auction website, with a 250-gramme piece starting at around US$13, roughly four times its normal price.

Just weeks before Norwegians will be expecting to eat plenty of buttery traditional biscuits and other homemade Christmas treats made with love and the liberal inclusion of dairy products, residents of the world's second-richest per-capita country can't even hope for help from a friendly neighbour who is rolling in butter.

Top dairy producer Denmark lies just across a narrow sea channel, but its stores of creamy butter will be kept out of the country by the high import duties of Norway, the only Nordic nation that does not belong to the European Union.

Still, the problem has certainly provided the Danes with a good laugh over their richly buttered breakfast toast.

Morning TV show Go' Morgen Danmark amid much hilarity offered a paltry 1,000 packets of butter on Wednesday to help ease the pain.

- Reuters