SYDNEY, May 21, 2012 (Dow Jones) -- Xstrata PLC's (XTA.LN) copper division is on track to increase its annual copper output by 60% by 2015, although decisions on further expansions of the business may be impacted by ongoing global economic uncertainty over the rest of 2012 and 2013, the chief executive of the division said Tuesday.

"Our growth profile should continue (although this will be) market conditions dependent when we look to make decisions over this next 18 months," Charlie Sartain said at a mining conference in Sydney.

He said acquisition remains a key pillar of Xstrata Copper's business strategy, and added that Xstrata's proposed merger with commodities titan Glencore International PLC (GLEN.LN) "will be the next major growth story for the group."