HARTFORD — More than 40 workers who weren't injured but lost their jobs in a deadly power plant explosion cannot sue several contractors for hundreds of thousands of dollars in lost wages, the state Supreme Court ruled Wednesday.

In a 6-0 decision, the justices said case law in most parts of the country does not permit such lawsuits.

Justice Richard Robinson wrote that allowing contractors to be held liable in such cases "appears likely to result in a significant increase in litigation, without a corresponding increase in the safe operation of industrial sites such as the power plant."

The ruling upheld two trial court decisions in 2013 that found that the companies did not owe the uninjured workers a "duty of care" because of public policy considerations.

The 2010 blast during construction of the Kleen Energy power plant in Middletown killed six workers and injured about 50 others. Authorities said crews were using natural gas at high pressure to clean out pipes and something sparked an explosion. The state later banned the "gas blow" practice.

Federal regulators fined several companies more than $16 million for 371 alleged safety and workplace violations, but those penalties were later greatly reduced in agreements the contractors reached with the federal government.

Joseph Barnes, a lawyer for the workers, didn't immediately return messages Wednesday seeking comment.

Proloy Das, an attorney for the contractors, said a ruling in favor of the workers would have "opened the litigation floodgates whenever there's an accident."

The defendants included plant owner Kleen Energy Systems LLC and O&G Industries of Torrington, the general contractor during construction. Several other companies involved in the construction also were sued.

Damage from the explosion was fixed, and the 620-megawatt plant is operating.