The Oklahoma Corporation Commission has ordered five public utilities to track savings from reductions in federal corporate income tax rates and develop a method to return that money to ratepayers.

The three-member panel took the action Tuesday after Attorney General Mike Hunter's office asked for the reduction for Oklahoma customers. The utilities involved are Oklahoma Gas & Electric, Public Service Company of Oklahoma, Oklahoma Natural Gas, CenterPoint Energy and Arkansas Oklahoma Gas.

Hunter filed his motions on the day President Donald Trump signed the sweeping overhaul of federal tax law that includes a reduction in the highest corporate tax rate from 35 percent to 21 percent. Hunter's office estimates the lower rates could create $100 million in windfall profits that he maintains should be passed on to Oklahoma residents.