OSLO - Winter sea ice around a Norwegian Arctic island has thinned to less than one meter (3 feet) since the 1960s, according to a study on Tuesday of a region that may be more attractive to oil firms because of climate change.

The Norwegian Polar Institute said ice around Hopen island southeast of the Svalbard archipelago had become more than 40 cms (16 inches) thinner in the past 40 years, in what it called the first long-term study of ice thickness in the Barents Sea.

"Since the year 2000 there have been no observations of ice thicker than one meter at Hopen, and the local air and water temperature has also risen," the Institute said in a statement.

Hopen is a narrow island about 30 km (19 miles) long off north Norway which is home to polar bears.

Ice around the entire Arctic reached a record low in September 2005, the end of the northern summer.

The U.N. Climate Panel says temperatures are rising more rapidly in the Arctic than on most of the planet because of global warming, stoked by human use of fossil fuels. Darker water and land soak up more heat than reflective ice and snow.

"The reduced see ice thickness at Hopen is in line with the generally reduced volume of ice in the Barents Sea and the whole Arctic," said Sebastain Gerland of the Polar Institute.

The study was being published in the journal Geophysical Research Letters, the Institute said.

Oil and gas companies are pushing north into the Barents Sea, seeking new reserves. Scientists say climate change may make the region less inhospitable and prices around $100 a barrel can justify exploration despite high costs.

Norway's biggest oil firm, StatoilHydro, operates the Snoehvit gas field in the south of the Barents Sea that opened in September last year.

Russian gas giant Gazprom holds a 51 percent share in the company that plans to develop the vast Shtokman gas field to the east. France's Total owns 25 percent and StatoilHydro 24 percent.

Editing by Tim Pearce
© 2008 Reuters