Updated at 4.06pm: Financial Secretary Henry Tang Ying-yen on Wednesday stressed the increasing importance that the mainland's economy was having in Hong Kong. In his second budget speech, Mr Tang said economic co-operation between Hong Kong and the mainland was developing at an impressive rate. This would mean that the Closer Economic Partnership Arrangement would have to be developed further. 'Our objective is to develop and expand Cepa still further. To this end, the government is now soliciting the views of relevant business sectors and will be holding discussions with the appropriate ministries of the Central Government,' he said. Mr Tang said the mainland was Hong Kong's largest trading partner and its second-largest source of foreign direct investment. Hong Kong was also the mainland's largest source of foreign investment. 'In the Pearl River Delta (PRD) region alone, for example, our manufacturing industry employs about 11 million workers, over three times the Hong Kong workforce,' he revealed. Mr Tang said about 240,000 Hong Kong residents regularly worked in China. 'In recent years, the mainland economy has been upgrading gradually. Its structure is also becoming more diversified. Such developments do pose constant challenges but they also open up new opportunities for Hong Kong.' Mr Tang said that as a long-term strategy, Hong Kong needed to continue strengthening its economic ties with Guangdong and other provinces and cities. 'This will extend our co-operation with the mainland, complement its further development and reinforce our own position as the region's premier bi-directional business platform.' The financial secretary said a good example of this was the mainland-Hong Kong Science and Technology Co-operation Committee which was established late last year. 'The committee had agreed to establish a working group to draw up specific plans for co-operation in four selected areas: automotive parts and accessory systems, radio frequency identification technologies, Chinese medicine, and integrated circuit design. He said this would help promote Hong Kong as a base for overseas enterprises to invest in the mainland and as a platform for mainland enterprises hoping to enter the international market. Mr Tang also emphasised that mainland companies were increasingly making their presence felt in Hong Kong. 'In Hong Kong mainland enterprises have raised over $900 billion since the introduction of H-shares in 1993,' he said. 'As at the end of last year, a total of 304 mainland enterprises had listed here, 22 per cent more than in 2003 and representing over a quarter of the total number of listed companies in Hong Kong.' Mr Tang said these enterprises accounted for about 30 per cent of stock market capitalisation. Trading in their shares last year constituted half the market's turnover. He said that last year alone, 44 mainland enterprises raised funds through listings in Hong Kong. 'The vast majority of mainland enterprises listed outside the mainland are quoted on our stock exchange. Of those listed in Hong Kong, only a minority are also listed in other overseas markets, and more than 70 per cent of their trading is conducted in Hong Kong,' Mr Tang added. He said this demonstrated that Hong Kong had further consolidated its position as the premier international capital formation centre for China.