The partners said they are still committed to the project, which would run to southern markets from the Mackenzie Delta on the Beaufort Sea. But they warned delays are jeopardizing what would be the continent's first major Arctic gas pipeline.

Spiraling cash demands from native groups in exchange for access to lands was a major reason behind the decision to halt work, Imperial said. It said governments should deal with many of the social issues that companies are being asked to solve as part of the negotiations on access and benefits.

"The whole issue of compensation, or dollars being paid for our lands, is being seen in the context of the moneys paid in southern Canada, and there's no comparisons that one should make," Nerysoo told Reuters late Monday.

"When you're talking about paying for affecting and changing the environmental conditions in our particular region, those are a totally different bases by which you measure."

The oil companies said last week the land issues and regulatory delays should be resolved before the hearings start in autumn.

The pipeline has been touted as a source of much-needed economic development for aboriginal people.

The lands of the 2,800 Gwich'in people make up a large part of the northwestern corner of the Northwest Territories. The companies also need deals with the Sahtu, Inuvialuit and Deh Cho First Nations.

Gwich'in talks with the companies focused on procurement and contracting, employment and education, as well as land deals, said Nerysoo, a former Northwest Territories premier.

"You don't come to a conclusion and measure the results of the demands of the aboriginal community purely in the context of what's on the table at the moment," he said.

"You measure it based on what the results of the negotiations turn out (to be), and it's unfortunate Imperial takes the view that these things aren't moving forward."

He said Gwich'in negotiators had believed the sides were getting close to a deal, especially on contracting and employment, when the producer group pulled the plug.

Deputy Prime Minister Anne McLellan said this week she agreed with the oil companies that the aboriginal communities are asking the industry to provide things that should not be part of access agreements, such as annual taxes.

The federal government has said it is searching for solutions, but has no legal role yet in the discussions.

"(The companies) are of the view that they're being asked to deal with issues that are beyond their responsibility, but the reality is that the project is going to have consequences on people, on environment," Nerysoo said.

Imperial has said it will discuss the socioeconomic aspects of the pipeline that are part of its 6,500-page application.

But it said governments will collect the taxes and royalties from the project and they should be responsible for using that money to tackle social issues.

The Deh Cho First Nations, which had already launched court action against the pipeline, pledged not to be "rushed, bullied or intimidated" by the oil companies' move.

"Imperial Oil says they want First Nations to 'be more reasonable.' What is unreasonable about asking the proponents of the (project) to treat First Nations governments as governments?" Grand Chief Herb Norwegian said in a statement.