In Business This Week

A BAFFLER FROM BUFFETT

WITH A BOOK LAYING OUT HIS financial wisdom on the best-seller list, investor-deity Warren Buffett has never had so many eyes on him. And on Feb. 14, the Omaha billionaire gave Buffett-watchers more to ogle. His Berkshire Hathaway holding company said it had raised its stake in American Express to 9.8% from 5.5% at the start of the year and had purchased an 8.3% interest in Pittsburgh's PNC Bank. He also sought permission to buy more AmEx shares. As usual, Buffett wouldn't say why. Still, word of his filings sent the stocks of AmEx and PNC higher and sparked a modest rally in other finance stocks.EDITED BY KEITH H. HAMMONDS