Teco Energy Inc., owner of the electric utility in Tampa, Florida, said it's exploring strategic alternatives such as a sale of the company.
Teco has retained Morgan Stanley to advise “in connection with exploring such strategic alternatives,” the company said in a statement.
Teco jumped the most in more than 12 years after online news service SparkSpread reported the company is for sale.
Teco rose 15 percent to $21.28 at 3:15 p.m. in New York before trading was halted. Earlier, it gained as much as 17 percent, the most since November 2012. Before today, the shares were down 9.3 percent for the year.