HONG KONG (Reuters) - Hong Kong Exchanges and Clearing shares rose 9 per cent on Friday, as investors welcomed China's announcement that it would allow cross-border share trading between Hong Kong and Shanghai.

HKEx shares were suspended on Thursday pending an announcement.

China's securities regulator said it would allow mainland investors to trade shares in designated companies listed in Hong Kong, and at the same time let Hong Kong investors buy shares in Shanghai-listed firms.

The move is set to boost trading volumes in Hong Kong, although HKEx stressed in a statement on Thursday that it has not yet reached agreement with its mainland counterparts on how cross-border trading would work.