Williams, TransCanada propose natgas pipeline

HOUSTON, March 13 (Reuters) - Williams Companies Inc (WMB.N: Quote, Profile, Research) and TransCanada Corp (TRP.TO: Quote, Profile, Research) on Thursday said they are are evaluating the development of a new natural gas transmission pipeline to move natural gas from the Rockies to markets in the western United States.

The proposed Sunstone Pipeline would be a 618-mile, 42-inch-diameter pipeline with capacity of up to 1.2 billion cubic feet per day, the companies said.

The project, proposed for service in 2011, would involve building a new pipeline nearly parallel to the existing Williams Northwest Pipeline system between the Opal Hub in Wyoming and Stanfield, Oregon.

Williams' Northwest system interconnects at Stanfield with TransCanada's Gas Transmission Northwest pipeline system. (Reporting by Anna Driver in Houston; Editing by David Gregorio)