CenterPoint Energy customers in Minnesota will see a 5.6 percent increase on the natural gas bills starting in October.

The interim rate hike was approved Thursday by the Minnesota Public Utilities Commission.

It will mean a $47.8 million increase in revenue for the utility, but is subject to refund with interest if the commission authorizes a lower rate increase after a review expected to take several months.

The Houston-based energy company is Minnesota's largest natural gas utility with 823,000 customers.

CenterPoint said it needs higher rates to cover investments including pipeline replacement. The interim rate increase will be a straight percentage applied to all customers' bills.

For its permanent rate hike, the utility wants to raise the basic charge, applied to all customers regardless of energy use, from $9.50 to $11.50 a month. The remainder of the increase would show up on the usage-based distribution charge. The cost of gas is a separate line on bills, with no markup by CenterPoint, and changes as the price fluctuates.

The rate hike comes less than two years after CenterPoint won a 3.9 percent increase. If approved, the 2015 increase would be the sixth in 20 years.

David Shaffer