The Alaska natural gas pipeline project backed by North Slope producers BP and Conoco Phillips plans this summer to seek customers that would ship gas through the proposed pipe. The Denali pipeline project's "open season" would start around July and run for 90 days. Open seasons are critical tests of a gas pipeline project. Enough customers are needed so that the owners can obtain the financing needed for construction.

The Denali project involves a roughly 2,000-mile pipeline from Prudhoe Bay to Alberta, where the gas could flow into existing pipeline networks serving Canada and the Lower 48. The project could cost tens of billions of dollars.

"While our objective is a successful open season, we are concerned that shippers may hesitate to make the financial commitments needed to support the project due to issues outside of Denali's control," Bud Fackrell, Denali president, said Tuesday. Those issues include new gas production in the Lower 48, the legal status of leases at the North Slope's second-largest gas field, and a desire for better certainty of state tax terms on gas, he said.

In April, Denali plans to submit to federal regulators the terms it expects to offer during the open season, the company said.