MINOT (AP) - Hess Corp., which has had a presence in the North Dakota oil industry for half a century, is expanding in the state and moving its state headquarters from Williston to this city.

New offices are planned next year in Minot and Tioga, and the global energy company's state headquarters will be moved sometime in 2009, said Mari Pat Sexton, a spokeswoman at the Hess corporate office in New York.

"It makes sense based on the location of our assets," Sexton said. "We evaluated our needs and found that we need to expand our offices."

Wayne Bieberdorf, manager of strategic projects for the company, said Hess will continue to have a presence in Williston.

"We have not really worked out those details, exactly how many people would move and how many would stay," he said.

Bieberdorf said the plan is in the preliminary stage and that it could take up to five years to complete.

Bruce Hicks, assistant director of the state's Oil and Gas Division, said the expansion of Hess indicates how much North Dakota's energy industry is booming.

"Not only is Hess expanding in oil, like a lot of companies are trying to do, but they're also expanding in (natural) gas," he said.

Hess, which has been in North Dakota since the early 1950s and is one of the leading energy producers in the state, says the oil-rich Bakken geologic formation is an opportunity for growth.

The Bakken encompasses some 25,000 square miles in North Dakota, Montana, Saskatchewan and Manitoba, and about two-thirds of it is in western North Dakota. Estimates of oil reserves are in the billions of barrels.

Sexton said the larger Hess presence in Minot will help recruit engineers to work in the Bakken.

"Hess is committed to growth in North Dakota," she said.

North Dakota's oil industry has been booming. The state's oil production totaled about 127,000 barrels a day in September, the latest figures available, according to the state Oil and Gas Division. The peak oil production in the state was about 148,000 barrels a day in 1984.

Oil and gas lease sales in North Dakota during fiscal 2007, which ended in September, totaled $9.3 million, according to the federal Bureau of Land Management.