HONG KONG • A long-delayed trading link between the exchanges of Hong Kong and Shenzhen in China made a disappointing debut yesterday, with markets on both sides of the border ending lower.

The link opens another door to the mainland's cloistered markets, allowing foreigners to buy shares in more than 800 Chinese firms for the first time, while also giving mainlanders further access to Hong Kong-listed companies.

Like the Hong Kong-Shanghai link two years ago, the scheme is being touted as China's latest effort to prove its capital markets are gradually opening. But by the close of trading, Hong Kong was down 0.26 per cent and Shenzhen's composite index had given up 0.78 per cent.

Only 21 per cent of the northbound trade allowed was taken up, while a little more than 8 per cent of the southbound quota was used up.

Huarong International analyst Jackson Wong said: "Investors were not expecting a spectacular open anyway, because investor sentiment is a little bit on the quiet side." That was mainly due to the weak yuan and concern that China would not open up capital flows in the short term, said Mr Wong.

Shenzhen is the world's eighth largest bourse with a market capitalisation of US$3.3 trillion (S$4.7 trillion) as of September. The Shanghai-Hong Kong link was launched in November 2014, giving foreigners access for the first time to Chinese companies not quoted elsewhere, and vice versa. But it has failed to excite traders.

Mainland accounts are valid for Shanghai and Shenzhen exchanges, so the latest link does not give access to the Hong Kong bourse to any extra investors. But it allows the existing ones to trade a further 101 smaller Hong Kong-listed firms.

Broker Neil Mclean said the long-term impact of the link should not be underestimated: "The real huge significance of this over a 10-year scope is the ability for China to come in to the rest of the world. China doesn't open its doors for fun." AGENCE FRANCE-PRESSE