AUGUSTA – Central Maine Power Co. said Friday it will lower its prices for electric delivery service to residential, commercial and industrial customers starting today.

Charges for residential and small-business customers will drop by about 10 percent. For an average residential customer using 550 kilowatt-hours per month, the savings will be about $3.50 a month, or a little more than $40 per year. Savings for commercial and industrial customers will vary by usage, but their costs should fall between 25 percent and 35 percent on average, CMP said.

“This will be a significant savings for all of our residential and small-business customers, and larger commercial and industrial accounts, too,” said Sara Burns, president of CMP. “That’s especially good news for everyone whose electricity supply prices are going up.”

The new delivery prices will save customers nearly $175 million over the three-year period from March 2008 to February 2011, CMP said. The savings are a result of declining stranded-cost expenses as long-term contracts for above-market power purchases expire and as obligations for the company’s former nuclear plant investments wind down.