Mining titan BHP Billiton Ltd.'s (BHP) long-term outlook remains strong and the global economy is recovering but it could still stall, the company's chairman said Thursday.

"This year started quite positively as the global economy reacted to substantial government-funded economic stimulus...however, in April of this year sovereign debt concerns re-emerged," Jac Nasser said at the company's annual general meeting.

He added: "It is still possible that the recovery could stall--government balance sheets remain weak and global trade and currency tensions continue to escalate."

Nasser said the European Union, U.S. and other developed countries still face ongoing challenges with regard to fiscal and financial stability.

But a structural shift in the global economy toward China and other emerging markets--including India, Russia, Brazil, and more recently Indonesia, Mexico and Turkey show promise for future growth as the forces of industrialization, urbanization and improved living standards continue to grip developing economies, he said.

Nasser said prices for commodities remain volatile due to concerns about the overall health of the global economy but he noted that BHP's diversified portfolio has reduced its exposure to price volatility.

-By Alex MacDonald, Dow Jones Newswires; +44 (0)20 7842 9328; alex.macdonald@dowjones.com