GAF Corp. and its vice chairman, James...

GAF Corp. and its vice chairman, James Sherwin, pleaded innocent to charges that they manipulated Union Carbide Corp.’s stock price after a takeover attempt of the much larger company fizzled in 1986. Lawyers for GAF and Sherwin entered the pleas in federal court in New York to the 10-count indictment returned last week by a grand jury. Sherwin, who could face a 50-year prison term and $15 million in fines if convicted, was released without bail. U.S. District Judge Mary Johnson Lowe did not immediately set a trial date. If convicted on all counts, Wayne, N.J.-based GAF could face $15 million in fines.