PHOENIX -- Electricity rates will be going up by an average of nearly 6 percent for customers of the Salt River Project.

SRP's board of directors approved the overall 5.9 percent increase to help pay for increased costs of natural gas and other fuel for power plants and electricity bought from outside the company.

Residential customers will see bills increase by an average of 5.1 percent. The average homeowner will see winter bills go up by $4.70 a month and summer bills increase by $7.89 a month.

The increase the board approved on Monday will go into effect on November's bills. SPR is making no additional profit on the fuel-cost adjustment.

SRP serves about 935,000 customers, primarily in Maricopa and Pinal counties.

(Copyright 2008 by The Associated Press. All Rights Reserved.)