Avista's natural gas prices in Idaho will likely increase 4.3 percent.

The utility filed its annual Purchased Gas Cost Adjustment to the Idaho Public Utilities Commission on Wednesday to reflect Avista's price to purchase wholesale natural gas.

This is a pass-through that reflects the price of wholesale natural gas, said Debbie Simock, Avista spokeswoman.

"It has no impact on company earnings," she said.

Simock said PGAs are typically approved by the state commission. Avista requested that the new rate become effective Nov. 1.

An Idaho residential customer using an average 63 therms a month could expect their bill to increase by $2.75 for a revised monthly bill of $58.78.

Avista natural gas rates decreased by about 30 percent in 2009. Simock said that, even if the increase is approved, the price will be about the same as it was in 2004.

The price in Washington is proposed to increase 4.6 percent.

The requested increases are due to the reduction in the refund being provided to customers related to wholesale natural gas costs in Avista's 2009 PGAs. Abundant natural gas supplies, combined with softening demand, have kept wholesale natural gas prices at lower levels over the past year, which have helped to partially offset the effects of the reduction in the 2009 refund.

Avista has 74,000 natural gas customers in North Idaho.

The Idaho increase would increase Avista's annual natural gas revenue by $3.1 million.

Meanwhile, a reduction in the benefits Avista customers receive under the Bonneville Power Administration's Residential Exchange Program resulted in a filing to increase electric prices for residential and small-farm customers in Idaho by 1.65 percent effective Nov. 1.

An average electric user of 1,000 kilowatt hours a month would see a $1.42 hike.

There would be no impact on Avista's earnings with the increase.

The exchange program provides a share of the benefits of the federal Columbia River power system to the customers of six Northwest investor-owned utilities. Avista applies the benefits it receives, which usually fluctuate annually, to customers as a credit on their monthly electric bill.

Both rate filings can be viewed at www.avistautilities.com or www.puc.idaho.gov. Comments will be accepted on the IPUC website.