PEORIA — State regulators on Thursday approved an order requiring Illinois utilities, including Ameren Gas and Illinois American Water to pass along their federal tax cut savings to customers.

The Illinois Commerce Commission approved the changes, called Variable Income Tax Adjustment Riders, that require each utility to credit consumers with the estimated savings beginning with their next billing cycle.

The tax cuts, passed last year by Congress and signed by President Donald Trump, reduced corporate income tax rates from 39 percent to 21 percent.

“The Commission’s orders Thursday will ensure that tax savings will be passed on to utility customers,” said Commission Executive Director Cholly Smith. “In light of steep reductions in corporate taxes it was vital to find a way to promptly pass savings to consumers. The Commission’s action does exactly that.”

The orders also apply to Peoples Gas, North Shore Gas and Nicor Gas in northern Illinois.

The commission said in the release that it worked with the utilities, as well as the Citizens Utility Board and the office of the Illinois Attorney General to develop the orders.

Both Ameren Illinois' electric operations in downstate Illinois and Commonwealth Edison in northern Illinois moved to implement the refunds earlier in the year.