State regulators on Tuesday moved a step toward rejecting a plan by Spain's leading electricity and natural gas utility to buy the parent company of several local energy firms in a deal valued at up to $3 billion. The state Public Utilities Regulatory Authority issued a draft decision saying that Spain's Iberdrola has not provided "any measurable or quantifiable commitments" that assure regulators that ratepayers will not be harmed by its plan to buy UIL Holdings Corp. In the deal announced early this year, the company would serve 3.1 million electric and natural gas customers in Connecticut, Maine, Massachusetts and New York.