Top investment: Chief Secretary for Administration Henry Tang (centre) tells radio listeners Hong Kong should work with other Pearl River Delta cities to create a core economic zone.

Hong Kong should work proactively with other cities in the Pearl River Delta as the region has the potential to become one of the world's core economic zones, Chief Secretary for Administration Henry Tang says.

Speaking on a radio talk show today Mr Tang said Hong Kong should welcome co-operation with Shenzhen in developing a modern services industry in Qianhai.

He said it is important for Hong Kong to get involved in the Qianhai development and to work closely with Shenzhen.

Meanwhile, Mr Tang said space has been reserved for a possible one-stop customs checkpoint at the future Guangdong-Shenzhen-Hong Kong Express Rail Link immigration tower.