The state regulatory board said neither of the proposed bids reflect the fair market value of Vermont Yankee and thus cannot, as a matter of law, be found to promote the general good.

AmerGen and Entergy Nuclear Corp. of New Orleans, Louisiana, have been engaged in a bidding war for Vermont Yankee. In November 2000, AmerGen offered $23.8 million for the unit. In January 2001, Entergy bid $50 million, more than twice AmerGen’s offer. AmerGen responded by raising the bid again with an offer valued at $51.5 million.

The board said the plant’s owner, Vermont Yankee Nuclear Power, may now proceed with plans to hold a public auction, or use any other process that will ensure a fair price.

Vermont Yankee Nuclear Power, which operates the plant on behalf of seven New England utilities, agreed with the decision by state regulators, but wants to conduct the auction quickly while market for nuclear plants continues to be strong. The company is aiming to complete the auction by early summer.

In addition to AmerGen and Entergy Nuclear, Constellation Nuclear of Baltimore, Maryland, and Dominion Energy of Richmond, Virginia, may participate in an auction.