* SPDR Gold TrustGLD, the world's largest gold-backed exchange-traded fund, said its holdings fell 0.23% to 878.54 tons on Monday from 880.55 tons on Friday. Dec 12 (Reuters) - Gold prices edged higher on Tuesday after hitting a three-week low in the last session, as the dollar eased, while investors awaited key U.S. inflation data and major central bank policy meetings for interest rate clues. * The Federal Open Market Committee's two-day monetary policy meeting will end on Wednesday with its interest rate decision and the release of its summary economic projections.