CHARLESTON, W.Va. (AP) — The West Virginia Public Service Commission says gas utility bills are expected to drop slightly as customers turn on their heat.

The agency said in a news release Friday that natural gas utilities serving almost all of the state have asked to lower the purchased gas portion of their rates by almost 4 percent to almost 6 percent.

The price of natural gas is determined by competitive markets, but the PSC examines the gas purchasing practices of gas utilities and ensures the utility did all it could to obtain a reliable supply at the lowest market price.

Gas utilities are permitted by law to recover the cost of purchasing natural gas. Customer gas rates are adjusted annually to account for the gas cost in a Purchased Gas Adjustment proceeding before the PSC.