At the same time. the prospect of a slump in manufacturing demand has reduced the appeal of silver, which gets about of its half of demand from industrial fabrication.
"Silver is half precious metal half industrial metal, and it hasn't been the safety play that gold has," said James Cordier, founder of Optionsellers.com in Tampa.
"Gold certainly has done extremely well with uncertainty around the world and with the idea that interest rates wont be rising. Until global growth comes up, the gold-silver ratio will continue to widen."
Gold for immediate delivery climbed 0.8 percent to $1,238.47 an ounce at 11:36 a.m. in New York. The metal is up 17 percent this year. Spot silver, down 0.6 percent on Thursday, has advanced 9.6 percent this year, while palladium has lost 14 percent.
Last week, the OECD cut its global growth forecasts, saying the economies of Brazil, Germany and the U.S. are slowing and warning that some emerging markets are at risk of exchange-rate volatility.
Holdings in gold-backed exchange-traded products rose 10 metric tons to 1,676.2 tons as of Wednesday, the highest in a year, data compiled by Bloomberg show.
Investors are now buying the metal on dips, rather than selling on rallies as they had done in previous years, Georgette Boele, an Amsterdam-based strategist at ABN Amro Bank NV, said by email. She earlier this month switched her gold outlook to bullish from bearish because of a more pessimistic view on the global economy.
• Spot platinum slipped 0.9 percent to $929.28 an ounce. The metal has climbed 4.2 percent in 2016.
• The BI Global Gold Mining Competitive Peer Group of 44 producers advanced 0.2 percent on Thursday. The index rose 38 percent this year.