Three Utah law firms handling a product liability lawsuit against the nation's biggest tobacco companies have joined a national group of lawyers involved in similar litigation.

Campbell Maack & Sessions, Burbidge & Mitchell and Winder & Haslam said they have accepted an invitation to work with the Castano Tobacco Litigation Group to "marshal forces and resources" on behalf of their clients.The trio of Utah firms is representing four Utahns in a suit that accuses tobacco companies of fraud and deceit in the manufacture and sale of tobacco products. They allege the companies conspired to conceal the high toxicity and addictive power of nicotine.

In statement released by the three firms, lead attorney Robert S. Campbell Jr. said joining the Castano Group will give the Utah plaintiffs immediate access to millions of coded and indexed documents, pleadings and depositions from other states.

"It will enable the Utah case to be set for trial on issues of class certification, liability and damages much more quickly," Campbell said.

Filed Feb. 13 in 3rd District Court, the suit seeks class-action status to include the claims of all nicotine-dependent Utahns and the survivors of those who have died from tobacco-related illnesses.

Lawyers say it could involve hundreds of thousands of plaintiffs and claims totaling more than $1 billion, making it the state's largest consumer fraud case.

Meanwhile, an earlier class-action lawsuit filed by a Utah County law firm on behalf of underage smokers has been moved to U.S. District Court.