Utility regulators on Wednesday approved a “standard offer” rate for electricity that’ll mean a $30-per-month increase for a typical residential customer of Central Maine Power.

The Maine Public Utilities Commission approved an 83% rate increase effective Jan. 1 based on a competitive bidding process. It was similar to an 88% increase approved the day before for Versant customers.

PUC Chairman Philip L. Barlett II reiterated that higher natural gas prices are driving up electric rates, “which have increased dramatically.”

The standard offer, based on competitive bidding, is the default option for consumers who don’t select an electricity vendor.

The rate increase applies to the electric supply portion of people’s utility bills. A separate charge is levied for transmission and distribution costs incurred by CMP and Versant to deliver the electricity to homes.

All told, an average CMP residential customer will see electricity bills grow from about $96 to about $126, regulators said.