AUGUSTA – Gov. John Baldacci has signed into law a bill that sets the stage for Maine’s possible withdrawal from ISO New England, operator of the regional power grid.

The legislation would trigger action if the state Public Utilities Commission determines that ending Maine’s membership in ISO New England is in the state’s best interest.

In that event, the PUC would have to order Maine’s three investor-owned transmission and distribution utilities to file a plan to form an alternative structure.

Baldacci opposes Maine’s membership in ISO-New England. Critics say Maine consumers pay more than their fair share of regional power rates.