Entergy Mississippi says customers will see an 18 percent reduction in their bills starting in October because the price of natural gas is falling.

The rates will be in effect through the end of December.

More than half of Entergy Mississippi’s electricity is generated using natural gas.

“Lower natural gas prices at the national level combined with Entergy’s efforts to minimize the impact of fuel costs in Mississippi means that our customers are paying much less for electricity today than a year ago,” Carolyn Shanks, president and CEO of Entergy Mississippi, said in a news release Tuesday.

Entergy said that since March, a bill for a typical residential customer using 1,000 kilowatt hours per month has fallen $40, or 31.5 percent.

A typical residential bill will decrease from about $107 to about $88 for every 1,000 kilowatt-hours used, the company said.

A year ago, natural gas prices doubled nationwide, partly because of damage caused by hurricanes Katrina and Rita on natural gas wells, refineries and pipelines in the Gulf Coast region.

Shanks said Entergy has been working to reduce the effect of high natural gas prices on customers. The company used a diverse fuel mix to power its generating plants and practiced hedging, which locks in low rates on natural gas purchases.

Entergy Mississippi provides electricity to more than 427,000 customers in 45 of the state’s 82 counties. It is a subsidiary of Entergy Corp., which serves 2.7 million utility customers in Arkansas, Louisiana, Mississippi and Texas.