BOSTON (AP) — Attorney General Martha Coakley said Wednesday she plans to convene a summit to discuss ways of controlling high energy costs that threaten the ability of Massachusetts' industries to compete with other regions.

Massachusetts has the nation's fifth highest overall energy costs, including electricity and heating, Coakley said in a speech to the Greater Boston Chamber of Commerce, but the state's industrial sector pays more than in any other part of the country.

"Energy costs play a crucial role for business decisions to come here, to grow here and to compete here," Coakley told the business leaders who gathered on the coldest morning so far this winter.

In her speech, she cited but didn't identify a large western Massachusetts manufacturer that paid an average 13 cents per kilowatt hour for electricity, more than twice that of competitors in Southern states.

Raytheon, one of the state's largest employers, pays an additional $1 million when the cost of a unit of energy rises by just a penny, she said.

The summit, bringing together energy and environmental experts along with representatives from government, business, utilities and government, would be held sometime this spring, she said.

The New England region did receive some encouraging news on the energy front on Wednesday in the form of a report that showed wholesale energy prices dropped by nearly 23 percent last year to their lowest levels since 2003. ISO New England cited falling natural gas prices and lower demand.

Still, energy costs continue to be cited by Massachusetts employers as a major impediment to expansion. And while little can be done about harsh New England winters, she said the summit would examine innovative solutions for improving energy efficiency and lowering transmission costs.

She said one goal would be to build on the 2008 Green Communities Act, which aims to increase energy conservation and renewable power use in Massachusetts.