Climate change, the global economic meltdown and the role of big water companies are on the agenda for thousands of delegates at a conference this week in Turkey focused on the world's water resources.

Global economic turmoil has sparked concerns that dwindling funds for investment in water infrastructure could create growing problems for the world's neediest. Depletion and pollution are already taking a toll.

"The water situation in the world is not going in the right direction," said Ger Bergkamp, director general of the World Water Council, organizer of the forum. "There is a matter of urgency to act."

Two-thirds of the world's population will face water shortages by 2025 as populations expand and ecosystems deteriorate, according to the International Union for Conservation of Nature, an environmental network based near Geneva.

"Climate change will be felt first and foremost through water, whether it be drought, floods, storms, ice melting or sea-level rise," Mark Smith, head of the union's water program, said in a statement. He said river basins and coasts must be protected because they provide water storage and flood control.

The World Water Council, based in Marseilles, France, holds a forum every three years. It was founded to exchange ideas about conservation and the development of water resources.

Group members include the World Bank, the International Committee of the Red Cross and the U.S. Corps of Engineers. Iraqi President Jalal Talabani is among leaders expected to attend the World Water Forum which opens in Istanbul on Monday.

Some non-governmental organizations accuse the forum of serving as a vehicle for big water companies to promote their own interests through privatization, denying the "human right" to water in impoverished communities around the world.

"It's really a big trade show," said Maude Barlow, founder of the Blue Planet Project, an Ottawa, Canada-based group that seeks to protect fresh water. "They deeply believe that water is a commodity to be bought and sold."