The Pennsylvania Public Utility Commission on Thursday voted unanimously to investigate a distribution rate increase request for PPL Electric Utilities Corporation.

The request proposes an increase in PPL's annual electric distribution rates of $167.5 million (18.5 percent). The commission investigation will determine what, if any, of the requested increase is justified.The investigation is customary, PPL said."This is a routine part of the PUC's deliberation process for utility rate requests, which we anticipated when we announced that we had filed the request. At that time we said we expected new rates, if approved, to take effect on Jan. 1," said spokesman Paul Wirth.Under the rate increase request, the monthly electric bill for an average residential customer using 1,000 kilowatt-hours per month would increase from $147.31 to $157.50 (6.9 percent).The request is suspended for up to seven months and will be assigned to the Office of Administrative Law Judge for public hearings and a recommended decision or settlement. A final decision must be made by Jan. 1, 2016.