By Arpan Mukherjee
Platinum continued to outperform gold as the complex extended overnight gains in Asia Thursday, helped by a stronger euro, worries about mine supplies from South Africa and renewed optimism about the Federal Reserve announcing some additional stimulus.
At 0459 GMT, spot platinum was at $1,551.70 a troy ounce, up $19.70 or 1.2% from its previous close.
The spread between gold and platinum continued to narrow as the threat of violence spreading to other platinum mines in South Africa cast a shadow over supplies. The country accounts for around 75% of global platinum output.
The spread has narrowed to around $111.40 from around $228 Aug. 15.
"Violence in South Africa is spreading and we could see the spread narrow further," analysts at ANZ said in a report.
Workers clamored for higher wages Wednesday at two more platinum companies in South Africa's mining heartland, less than week after a violent protest at Lonmin PLC's (LMI.LN) Marikana mine left 44 dead.
Jonathan Barratt, chief economist of Barratt's Bulletin, said in a report that the effect of the Lonmin strike "looks to be spilling over to other mines" and could affect production of other metals too.
"There is real potential of a supply crunch occurring" in platinum, Mr. Barratt added.
The minutes of the Federal Open Market Committee's last meeting, which were released overnight, helped support prices, with expectations for additional stimulus remaining elevated, Phillip Futures analyst Lynette Tan told Dow Jones Newswires.
"Many members judged that additional monetary accommodation would likely be warranted fairly soon unless incoming information pointed to a substantial and sustainable strengthening in the pace of the economic recovery," according to the minutes from the July 31-Aug. 1 meeting.
"If they do not launch [additional] monetary easing, it will probably be too late for the results to flow in before the U.S. Presidential elections at the end of the year," Ms. Tan said.
A stronger euro underpinned prices as dollar-denominated commodities become more affordable to holders of other currencies when the greenback retreats.
The euro was at $1.2538 compared with $1.2528 late Wednesday in New York.
Silver followed gold higher as hopes of stimulus helped extend its recent rally. The metal has risen 7.1% since Aug. 17.
A Singapore-based trader said speculative U.S. investors have been behind much of this week's rally, adding that physical markets in Southeast Asia are very slow, with Malaysian and Singaporean buying especially sluggish.
Spot silver was at $30.22/oz, up 49 cents and palladium was at $633.30/oz, up $4.30 from its previous close.
Clementine Wallop contributed to this article.
Write to Arpan Mukherjee at arpan.mukherjee@wsj.com