A senior?World Bank official said on Sunday that China faces key challenges in becoming the world's top economy by 2030 or 2040.

Addressing the first day of the China Development Forum 2005, Shengman Zhang, managing director of the World Bank, said the country has to transform its mode of economic growth, which is currently characterized by low efficiency and excessive consumption of resources and energy, to an efficient one, not simply relying on high growth of investment.

China must also improve its market operating efficiency and improve corporate efficiency, he said.

Zhang said rapid and sustainable economic growth needs to be maintained while controlling growing negative environmental impact through improved efficiency in energy and water consumption.

Compared with industrialized nations, it costs China about 150 to 200 percent as much energy to produce per-unit gross domestic product, he said.

Inequalities also continue to grow, which are a by-product of much of the country's development so far, said Zhang.

China needs the help of other members of the international community to address these challenges, said the vice-president.?

It has become the world's third largest trading nation and is projected to become the biggest trading nation in 2020, he said.?

(Xinhua News Agency March 21, 2005)