A Florida-based CEO of a regional freight railroad company has sued Greenberg Traurig for $10 million in damages he says he and his companies incurred in a lawsuit stemming from a stock sale the law firm advised on.

Gary O. Marino of Boca Raton, along with Patriot Equity LLC and other related companies, sued Greenberg Traurig in Palm Beach County circuit court Wednesday, according to Marino’s lawyer, Warren R. Trazenfeld in Miami.