Construction will begin Thursday on an inter-city subway linking two cities in South China's Guangdong Province,heralding faster rail services in the Pearl River Delta area, one of the country's economic engines.

The 32.16-km-long subway line linking Guangzhou, capital of Guangdong, with Foshan City, west of Guangzhou, will shorten travel time between Foshan city and downtown Guangzhou to about 40 minutes, down from 50 minutes.

At an estimated cost of 14.7 billion yuan (1.9 billion US dollars), the subway has 21 stops and will go into operation in 2012. The line will be linked to four subway lines in Guangzhou.

The inter-city subway is one element of a planned fast rail service network along the Pearl River Delta area, adjacent to Hong Kong and Macao.

The network will have seven inter-city rail lines with a total length of 588 kilometers, connecting Guangzhou with Dongguan, Shenzhen, Zhuhai, Zhaoqing and Foshan. Four of them have been completed and all the lines will be completed by 2020.