Nord Stream, the consortium that operates a natural gas pipeline that ships Russian gas to western Europe via the Baltic Sea, said Friday it is considering further expanding the pipeline.

In a written statement, the consortium, led by Russian gas monopoly Gazprom OAO (GAZP.RS), said its shareholders have asked the company to conduct "a feasibility study" into possible options to further increase capacity.

"Over the next eight months, Nord Stream will make an assessment of various criteria of up to two potential additional pipelines, including technical solutions, route alternatives, environment and financing," the company said.

It didn't say by how much the expansion could increase gas shipping capacity. A Nord Stream spokesman said the exact amount of the possible capacity expansion will be determined in the feasibility study.

"We will look at how much additional gas will be needed in northwestern Europe in the coming decades" and make an decision accordingly, the spokesman said.

He added that the feasibility study would be followed by further examinations--including the environmental impact assessment of the project--and subsequently an approval process. An investment decision by Nord Stream shareholders would then follow as a third step.

The first of Nord Stream's two parallel pipelines started operations in November last year. Each of the pipelines is around 1,220 kilometers long and has a transport capacity of 27.5 billion cubic meters per year.

Construction work on the second pipeline has recently been concluded. The first expansion will increase Nord Stream's capacity to 55 billion cubic meters in late 2012.

Gazprom owns 51% in Nord Stream with BASF SE's (BAS.XE) Wintershall unit and E.ON AG (EOAN.XE) each holding an interest of 15.5% in the pipeline company. Dutch gas grid operator Gasunie and French utility GDF Suez SA (GSZ.FR) each own 9% of the shares.