A key federal regulator has told Congress that substantial progress is being made on an Alaska natural gas pipeline but that it is still concerned about the challenge of reviewing applications from rival proposals.

Joseph Kelliher, chairman of the Federal Energy Regulatory Commission, told Congress in a statement accompanying his agency's report that the pipeline has made more progress in the past six months than in any other period covered by FERC's annual reports to Congress on the Alaska project.

TransCanada Corp., a Canadian pipeline company, just launched a state-sanctioned project, and a venture by BP and Conoco Phillips -- two companies with rights to much of the North Slope's gas -- have launched another. Both proposals if they proceed to construction would cost tens of billions of dollars and would carry the gas to Alberta, Canada.

"The competition for the project is a positive indication of serious interest by major industry players. This should all be resolved, ultimately, in the energy and financial marketplaces, and FERC stands ready to act once that takes place."

Kelliher said reviewing multiple projects "would greatly challenge the commission staff, the other agencies on the federal interagency team, and state agencies. Clearly, everyone must work together with the shared goal of getting a project built."

FERC said in its sixth annual report that it is neutral and "has no basis to prefer one project over another."