JAKARTA, May 4 : Indonesia's trade surplus expanded in March to $3.32 billion, the largest since September, official data showed on Monday, even as exports fell in annual terms. The March surplus was larger than both the median forecast of a $2.41 billion surplus in a Reuters poll of economists and a $1.28 billion surplus a month earlier. The resource-rich country has run sizeable surpluses in recent years, but analysts expect exports will be affected by slower global demand due to the Middle