0539 GMT [Dow Jones] UBS report points to market talk that China's central bank and/or Middle Eastern central bank aggressively buying gold. UBS cannot confirm talk, but sees in this another bullish factor for gold; notes current tension between Iran, U.N. Security Council over Iran's nuclear ambitions has some parallels to Iranian hostage crisis that contributed to gold hitting $850 in January 1980. Gold now quoted at $544.55.(JSH)
