BOSTON – Attorney General Thomas Reilly has asked federal energy regulators to investigate a proposed reorganization of the region’s wholesale electric market, arguing the plan will likely raise energy prices for thousands of consumers. Maine Gov. John Baldacci countered, however, that the plan has the potential to reduce electricity costs in Maine by 7 percent to 10 percent.

In a motion filed Wednesday with the Federal Energy Regulatory Commission, Reilly said the plan by Independent System Operator-New England, which manages the region’s power grid, should be delayed until it can be studied further.

Under the current system all of New England is treated as one wholesale power market, with the costs of “electrical congestion” in areas like greater Boston and southwestern Connecticut spread to customers throughout the region.

The new plan would break New England into eight regional markets, each with its own wholesale price.

ISO has said the actual wholesale price increase could be smaller as new power plants, including one in Everett, are put into service this winter and spring.

In a letter dated Feb. 4, Reilly asked ISO to delay the plan.

Reilly argued in Wednesday’s motion that the plan could force Massachusetts’ retail consumers “to pay millions of additional dollars to generators without any benefit in congestion reduction or cost savings.”

However, Maine Gov. Baldacci on Wednesday praised the plan to implement location pricing.

He said the Maine Public Utilities Commission estimates that Maine citizens pay an extra $9 million in “congestion uplift charges,” even though Maine does not suffer from congestion.