Norway 's ruling three-party coalition Friday announced it will carry out an assessment of the environmental impact of exploring for oil and gas in the Barents Sea but said it will delay the start of a study in the Lofoten archipelago of the Norwegian Sea , reaching a compromise on a controversial issue.

Prime Minister Jens Stoltenberg said at a press conference that an environmental impact assessment study of the
Barents Sea , a key step toward exploration, will start as soon as it has reached a final boundary agreement with Russia .

The government said it will delay environmental assessment in the Lofoten region during the current parliamentary period that runs until 2013 but will start collecting information that could be used in a possible future impact study.

Friday's announcement will be cheered by environmental organizations but the decision will come as a hard blow to oil companies eager to explore new and untapped areas as they face a rapid depletion of their existing
North Sea reserves.

The petroleum sector is
Norway 's largest industry and accounts for 47% of its total exports. In 2008, the country was ranked as the world's sixth largest oil exporter and the 11th largest oil producer. It was the second largest gas exporter in the world, and the fifth largest producer of gas.