BISMARCK, N.D. (AP) — Bismarck-based WBI Energy Inc. said Thursday that it is gauging demand for a pipeline to move natural gas from western North Dakota's booming oil patch.

The company says the proposed pipeline route would begin near Williston and connect to an existing natural gas pipeline near Moorhead, Minn.

WBI is a subsidiary of MDU Resources Group Inc. of Bismarck. MDU Resources President David Goodin says the pipeline system could serve North Dakota, Minnesota, Wisconsin and other Midwest markets.

The project could initially move 400 million cubic feet of natural gas daily. The company estimated the project's cost at more than $650 million.

Natural gas is a byproduct of oil production in North Dakota. About one-third of natural gas is being flared, or burned off as an unwanted byproduct of crude production.