THE foundation-laying ceremony of Sky Central Plaza took place yesterday in Guangzhou's Tien Ho district. Sky Central Plaza will be Asia's tallest building and the fourth-tallest in the world upon completion in 1996. It is being built by Kumagai SMC Development Guangzhou Ltd, which is a joint venture between Kumagai Gumi (HK) and Shell Electric Manufacturing(Holdings). The site of the development covers an area of 23,239 square metres. There is to be an 80-storey main tower with 131,000 sq m of prime office space. Also included in the plaza are two residential blocks and a central commercial development. The total cost of the development, including land, is three billion yuan (about HK$4 billion at the official rate). At an opening address, Guangzhou Mayor Li Ziliu said: ''We welcome foreign firms who want to invest in Guangzhou, and encourage them to continue to invest in our city. ''I call on all enterprises to support the development of the Tien Ho district into the business and commerce centre of Guangzhou. Sky Central Plaza is a leading development for Tien Ho, and for the city and the province,'' he added. The development was designed by Ng Chun Man & Associates Architects & Engineers, which also designed Central Plaza and the Convention and Exhibition Centre.