Countywide

San Diego Gas & Electric has asked the state Public Utilities Commission to tack $6.3 million on to the $120.8-million rate decrease ordered by the commission last month.

If the PUC agrees with SDG&E;’s request, typical monthly residential bills (based on 400 kilowatt hours of electricity and 40 therms of gas) will drop by 13 cents, to $62.27.

When the PUC set SDG&E;’s 1986 rates in a December decision, it ordered the utility to decrease its typical residential monthly bill by $3.79, beginning with January billings.

An SDG&E; spokesman said the rate decrease request was prompted by “several inconsistencies between the language in the (PUC) decision and the (December) rate change authorized by the PUC.”