First Union Corp. of Charlotte, N.C., said...

First Union Corp. of Charlotte, N.C., said the U.S. Office of the Comptroller of the Currency approved its planned purchase of Richmond, Va.-based Signet Banking Corp. in a transaction worth about $3.4 billion. . . . British Airways said it would ban smoking on all of its flights beginning in March. . . . Nissan Motor Co., Japan’s second-largest auto maker, said operating profit rose to $407.34 million in the first half ended Sept. 30 from $306.77 million a year earlier. Worldwide sales grew 2.2% to $14.32 billion, with export sales up 14.1% and domestic sales down 6%.