Gold erased early gains that pushed it past the psychological $1,400 mark to an 11-week high, slipping on uncertainty over whether the U.S. Federal Reserve will wind back its stimulus measures from next month.
Spot gold was down 0.1 percent at $1,394.79 an ounce by 0027 GMT. It had gained 1.6 percent on Friday after weak U.S. home sales.
The metal breached the $1,400 mark early on Monday, jumping to a 11-week high of $1,406.01.
The Fed could announce a cautious first step in tapering bond purchases at its meeting next month, provided there were no "really worrisome" signs the economy was faltering, a top U.S. central banker said on Saturday.
South Africa's National Union of Mineworkers gave gold mining companies seven days on Saturday to meet its demand for pay rises of up to 60 percent or face strike action.
SPDR Gold Trust, the world's largest gold-backed exchange-traded fund, said its holdings rose 0.72 percent, or 6.61 tonnes, to 920.13 tonnes on Friday.
Hedge funds and money managers boosted bullish bets in gold futures and options to their highest level since early February, buoyed by the uncertain timing of the Fed's planned unwinding of its bond-buying stimulus, a report by the Commodity Futures Trading Commission showed on Friday.
ETF Securities, a pioneer of exchange traded funds as a tool for investors to buy into gold at a time when prices were rising, offered to let them swap shares for coins subject to a fee charged by Britain's Royal Mint.