By a 7-5 vote, the full 11th U.S. Circuit Court of Appeals has cleared the way for a Florida lawyer to sue the Nasdaq Stock Market for more than $600,000 he says he lost by investing in WorldCom.

Nasdaq and its former parent, the National Association of Securities Dealers, had sought the full court’s help after an 11th Circuit panel voted 2-1 last year to deny the two entities immunity from Steven I. Weissman’s claims. Weissman, a sole practitioner from Hollywood, Fla., claims that Nasdaq’s television and print advertisements fraudulently induced him to buy WorldCom stock by touting the stock’s virtues. The company went bankrupt in 2002 and its former president, Bernard J. Ebbers, is serving a 25-year sentence for fraud and conspiracy.