Berlin (AP) - Connecticut's biggest utility asked regulators Thursday to allow it to charge customers $414 million for costs related to five destructive storms last year and in 2011, a request that would increase the typical customer's bill $3 a month.

Storm repair costs totaled $462.3 million, Connecticut Light and Power said. The costs that the utility wants reimbursed exclude $8.3 million set aside in a storm reserve fund. Northeast Utilities, its parent company, also agreed to exclude $40 million as part of its deal with the state for its $5 billion purchase of NStar last year.

The charges would be implemented over six years. Rates would not change until December 2014 as part of the Nstar agreement.

"The damage from these natural disasters and the response to complete repairs was extraordinary and unlike anything in CL&P history," said Bill Herdegen, the utility's president and chief operating officer.

"Typically, storms of this magnitude strike years or decades apart, but in 16 months, we experienced four of the company's 10 most devastating storms."

About $175 million is related to the October 2011 nor'easter and $156 million for Superstorm Sandy in 2012, the utility said. The remaining costs are associated with Tropical Storm Irene in 2011 and two other major storms in June 2011 and September 2012.

Hundreds of thousands of customers were without power during and immediately after Irene and the freak October nor'easter. State legislation imposed tighter oversight of CL&P, which was harshly criticized by elected officials and state regulators.

CL&P failed to get adequate help before the October 2011 storm and its response was deficient, the Public Utilities Regulatory Authority said last August.

There is no question the five storms caused widespread damage, but the claimed costs must be reviewed closely and carefully to ensure that ratepayers are charged no more than was prudent and necessary, state Attorney General George Jepsen said in a statement.

He said he will "carefully review this filing to help protect ratepayers from unnecessary or inappropriate charges."

CL&P said the costs include bringing in outside line and tree workers, replacing damaged equipment and staffing the 24-hour response.