BEIJING, March 24 (Xinhua) -- China would obtain greater economic benefits and improve energy efficiency by adopting a more concentrated pattern of urbanization, according to a report released here Monday by the McKinsey Global Institute, McKinsey and Co.'s economics think tank.

    "An urgent shift in focus from solely driving GDP growth to an agenda of boosting urban productivity is not only an opportunity but a necessity," said the report.

    A more concentrated pattern of urban growth would produce 20 percent higher per capita GDP than the current pattern, have higher energy efficiency, and contain the loss of arable land, its said.

    It would also help cluster the most skilled workers in urban centers which would be major engines of economic growth.

    The pattern would produce 15 "super cities" with average populations of 25 million people or 11 clusters of cities with combined populations of more than 60 million, it said.

    China's urban population would expand from 572 million in 2005 to 926 million in 2025 and 1 billion in 2030, the report forecast. Of the 350 million people China would add to its urban population by 2025, more than 240 million would be migrants.

    By 2025, China would have 221 cities with more than one million inhabitants each. Meanwhile, urban areas would generate 95 percent of China's GDP, up from the current 75 percent, it said.

    "Continued growth of China's cities will ensure that China meets its target of quadrupling per-capita GDP from 2000 levels by2020."

    But the report warned the urban population growth would put pressure on many cities, including the challenge of managing the expanding populations, securing sufficient funds for social services and dealing with demand and supply of land, energy, water and the environment.

    Urban consumption would reach 21.7 trillion yuan (3 trillion U.S. dollars) in 2025, taking 33 percent of the GDP, compared with25 percent in 2005, it said.