WASHINGTON - The International Monetary Fund(IMF) on Wednesday sharply revised its 2009 world economic growth projections downward to 0.5 percent, the lowest rate since World War II. "Despite wide-ranging policy actions, financial strains remain acute, pulling down the real economy," said the IMF in its updated World Economic Outlook. Accordingly, the world economy is projected to increase by only0.5 percent in 2009, down by 0.75 percentage points from the projections in November. Advanced economies are expected to contract 2.0 percent in 2009,the first such fall since World War II, with a cumulative output loss comparable to the 1974-75 and 1980-82 periods. In November, the IMF projected the advanced economies to contract 0.3 percent in 2009. The IMF now expects the U.S. economy to contract 1.6 percent in2009, sharply down from its estimate of a 0.7 percent growth issued just two months ago.