* FAO food index falls for fourth month in row to 201.8 points
* FAO raises cereal production, stocks forecasts
* Economist says price declines may be close to bottom (Adds detail, economist quote)
By Catherine Hornby
ROME, Sept 5 (Reuters) - Global food prices fell in August for the fourth month running, according to the United Nations' food agency which again raised its 2013/14 ...