Utah Power & Light officials Friday filed documents with the Utah Public Service Commission seeking approval to decrease rates by $17.9 million annually beginning Dec. 3.

The rate reduction - the fourth one this year, UP&L officials said - will cut rates by 2.5 percent, or about $12 per year for the average residential customer.UP&L officials said the company has not had a general rate increase since 1984 and the four rate reductions in 1988 have now cut rates by 6 percent.