BEIJING (Reuters) - China's government released on Sunday a framework to develop sprawling urban areas along the Yangtze River as it moves forward with a decade-long ambition to turn the Chinese heartland into a major economic belt.

Although no specific investment details were released, the State Council, China's cabinet, said on its website it would designate 317,000 square kilometres along the river to become urban areas, hosting transportation and energy projects.

The designated urban development area will span the three provinces of Hubei, Hunan and Jiangxi near and around the metropolitan areas of Changsha and Wuhan.

China's top leadership has outlined plans to turn the Yangtze, which runs from China's western highlands and empties into the East China Sea near Shanghai, into an economic axis that would catch up with China's highly developed coastal regions.

(Reporting by Gerry Shih; editing by Clelia Oziel)