Connecticut is asking for the money to be returned, plus changes in the way ISO-New England, which oversees the power grid, monitors the power market to ensure independence.
The federal hearing is a "significant step forward for electric consumers in Connecticut who will finally get an answer as to why the power they paid for was never delivered and where exactly did their hard-earned money go," Rell said in a prepared statement.
Lawrence McDonnell, a spokesman for Constellation Energy, dismissed that assertion.
"The governor's claim is without merit and unsupported by the facts. Our company at all times followed both the spirit and letter of rules," said McDonnell, calling Constellation's moves "appropriate and prudent" responses to the market.
"All of the transactions in question were conducted openly and in full view of the ISO market monitors and various regulators charged with ensuring market fairness," he said.
The company is "prepared, if necessary, to fully defend our actions in the NY and ISO-New England market," he added.
Brookfield Energy Marketing Inc. also takes issue with Connecticut's claims. Zev Korman, a company spokesman, said there are "inaccuracies" in the accusations. He declined to comment further but pointed to a written statement in which he said that federal regulators acknowledged that the state provided little evidence to support its allegations.
Erin O'Brien, a spokeswoman for ISO-New England, based in Holyoke, Mass., said that it will willingly participate in the hearings.
She said its market monitoring structure is "long-standing" and stems "from a carefully planned structure broadly supported by regional stakeholders."