BEIJING, Jan. 24 (Xinhua) -- Beijing will shut down 500 manufacturing companies this year, to further move its non-capital functions out of the city, Beijing's acting mayor said Wednesday in a government report.

More than 40 state-owned companies will be moved out of the city proper, Chen Jining said at the opening of the first session of the 15th Beijing Municipal People's Congress.

Beijing plans to cap its population at 23 million by 2020 to address "big city diseases," including traffic congestion and pollution.

To meet the target, Beijing has taken measures to move non-capital functions away from the city, such as relocating wholesale markets and closing polluting factories.