Mountain Fuel Supply Co. said gas rates should stabilize during the coming heating season, after nine consecutive rate reductions in the past three years.

The company's annual "winter outlook" report said no "significant increases in gas costs are anticipated in the coming months," as a current surplus of gas continues to keep rates relatively stable."Gas costs will continue to fluctuate according to market conditions," Mountain Fuel president D.N. Rose said. "But all indications are that the market will remain stable and any fluctuations should be moderate."

Mountain Fuel customers' gas bills have fallen 10 percent through nine separate rate reductions due to well-controlled operating costs. As a result, the average residential customer is paying about the same rates as in 1983, a company spokesman said.

The amount of each individual customer's bill will depend on usage. If cold weather sets in soon or additional appliances are employed, the spokesman said, the total annual bill could be higher than last year's.

Natural gas consumption among Mountain Fuel's industrial customers has increased 14.8 percent in the past year. This has been caused by the growing number of industrial users buying low-priced natural gas directly from producers then contracting with Mountain Fuel to transport the fuel.

Mountain Fuel's ability to increase its industrial load through sales and transportation service, which cover a large portion of fixed costs, is critical to keeping residential rates stable, Rose said.