Buffett pessimistic on economy: CNBC (Reuters) - July 12 (Reuters) - Warren Buffett made some of his most pessimistic comments on the economy in recent memory on Thursday, telling CNBC that things have slowed in the United States in the last six weeks. Buffett, in a live interview, said Europe had also experienced a "pretty fast" slowdown in recent weeks as spending declined. The 81-year-old "Oracle of Omaha" said that even as the economy cooled off, residential housing was starting to pick up, albeit off a low base. Buffett's Berkshire Hathaway is heavily exposed to residential construction and real estate sales, and he has said the economy would really pick up only when the housing market finally turns around. Still, Buffett struck a much more bearish note than he has in the recent past, having said before that the U.S. economy was picking up slowly. He told CNBC he did not know precisely why things had slowed of late. Reporting by Ben Berkowitz; Editing by Bernadette Baum