National Grid files plan to lower rates

National Grid said it wants to reduce rates for natural gas and electricity customers in Massachusetts by May 1.

The utility has filed a proposal with the state Department of Public Utilities to lower the price of gas by nearly $1 per therm - from $1.49 to 51 cents. Electricity rates would drop from 12.6 cents to 9.7 cents per kilowatt hour.

The rate reductions - which reflect lower market prices - would save residential customers who use natural gas an average of $50 a month, according to National Grid, while electricity customers would save about $15.