Homeowners and businesses in the Colorado Springs area will see their gas bills increase this fall.
Aquila and Colorado Springs Utilities are increasing rates after wholesale natural gas costs rose more than 30 percent nationally.
Aquila spokesman George Minter says company officials haven't determined how much more customers will have to pay.
The increase will be the third straight annual increase for Aquila.
Minter says prices are being driven in part by utilities' increasing use of gas-fired turbines to generate electricity and large industrial businesses switching from oil to gas. Natural gas is also used more during cold winters.
The Colorado Springs City Council, which regulates Colorado Springs Utilities, would have to approve the rate hike.