* Holdings of SPDR Gold Trust GLD, the world's largest gold-backed exchange-traded fund, fell 0.2% to 998.46 tonnes on Wednesday from 1,000.21 tonnes on Tuesday. Sept 16 (Reuters) - Gold prices were steady on Thursday as investors awaited signals on the Federal Reserve's timeline for tapering pandemic-era stimulus measures, after softer-than-expected U.S. inflation data fuelled some uncertainty. * Production at U.S. factories slowed sharply in August as Hurricane Ida forced plant closures and an ongoing microchip shortage curbed motor vehicle output, but manufacturing remains strong amid lean inventories.