CONCORD, N.H. – A Florida utility told New Hampshire regulators Monday that its plan to buy a majority stake in the Seabrook nuclear power plant would lead to lower electric rates.

Florida Power & Light hopes to buy an 88 percent stake in Seabrook for $837 million. The deal, announced in April, is expected to be completed by the end of the year.

A lawyer for Public Service of New Hampshire, which built the plant, said the sale would bring customers a 6 to 7 percent rate reduction by 2005.

But a Walpole-based group objected to the proposed sale.

The Aziscohos Lake Preservation Committee said Florida Power & Light has a poor environmental record in Maine, where it owns dozens of hydroelectric stations and power plants.

Alan Johnson, co-chairman of the environmental group, which is named after a lake in western Maine, accused Florida Power & Light of destroying wetlands and failing to preserve water quality in that state. He also questioned the high price tag.

“I own a business and I become suspicious when someone offers to pay me more than something is worth,” Johnson told the three-member state Public Utilities Commission. “I become suspicious when someone promises one thing and then does another.”

New Hampshire officials have said the amount offered for the plant is $300 million to $400 million more than expected. Art Stall, senior vice president of FPL’s nuclear division, said FPL would benefit from gaining a nuclear energy foothold in the Northeast.

“It’s a big plant, it’s new and it is in excellent condition,” Stall said. “You’re looking at a plant that can run into 2049. When we looked at it and did the math, it was a win-win situation.”

Stall also defended his company’s environmental record and said it has won awards for its service.

The hearing was to continue for several days. Regulators in New Hampshire, Connecticut and Massachusetts must approve the sale.

The 1,161-megawatt plant near the Atlantic Ocean began operating in 1990.

Florida Power & Light, Florida’s largest electric utility, serves 3.9 million households in 34 Florida counties.