Gas and electric rates for Puget Sound Energy customers could be headed for an increase.

Puget Sound Energy on Oct.1 filed three separate rate-adjustment requests with the state Utilities and Transportation Commission (UTC). Two would reduce customer utility bill credits, resulting in a modest increase — less than $2 on the average monthly residential natural gas bill and less than a dollar on the average monthly residential electric bill effective Nov. 1, 2010.

The third seeks a rate increase of 2.3 percent that PSE has requested be effective Feb. 1, 2011 to recover increased costs to operate, maintain and upgrade the utility’s natural gas system.

The two credit adjustments, which are directly passed through to customers, include a Purchased Gas Adjustment (PGA) increase averaging 1.9 percent for all customer groups with natural gas service, and a 1 percent increase in residential electric rates. PSE makes no profit on these adjustments.

The PGA increase reflects a reduction of a credit included in current rates for the cost of natural gas supplies PSE purchased for customers. The other involves a decrease in the federal power benefits passed through to PSE’s residential and small farm customers as a monthly bill credit under the Bonneville Power Administration’s (BPA) Residential Exchange Program.

The third request, which is expected to go through a rigorous regulatory review, proposes a modest natural gas rate increase to recover increased costs incurred by PSE to operate, maintain and upgrade the utility’s natural gas distribution system.

The PGA filing would increase a typical household’s natural gas bill (based on 68 therms of average monthly usage over a 12-month period) by 1.9 percent, or $1.56, to $82.91 — about what PSE customers were paying in 2007.

The lowering of the BPA credit, listed on PSE bills as “Energy Exchange Credit” would increase a typical household’s electric bill (based on 1,000 kilowatt-hours of average monthly usage over a 12-month period) by 1 percent, or 98 cents, to $100.66.

PSE’s natural gas distribution charge proposal requests a revenue increase of $24.4 million, or 2.3 percent, in natural gas rates. If approved, the change would increase a typical household’s natural gas bill (based on 68 therms of average monthly usage over a 12-month period) by 2.6 percent, or $2.08, to $83.43.