BISMARCK, N.D. (AP) — Montana-Dakota Utilities Co. is asking North Dakota regulators for a 3.3 percent increase in its natural gas rates. The request would raise a typical residential customer’s natural gas bill by about $1.82 a month.

North Dakota’s Public Service Commission on Wednesday began a three-day hearing on the proposal.

MDU’s proposed natural gas increase would raise $3.6 million in additional revenues for the Bismarck-based company each year. MDU says it needs additional money to operate and maintain its natural gas pipeline system.

The Minot Air Force Base, AARP, and PSC staff are questioning the need for the rate increase.

The utility has about 109,000 North Dakota customers.