GAF Corp. sold about half its Union Carbide stock.

GAF spokesman Shellie Roth said the company sold 5.8 million shares on Monday, but she declined to elaborate on the sale. Roth said GAF, which manufactures chemicals and building materials, retains 4.6 million shares of Union Carbide, or 4.9%. In 1985, GAF failed in a takeover attempt of the much bigger Union Carbide, based in Danbury, Conn.