Hong Kong’s stock exchange is in discussions with bourses in mainland China, including Shanghai, about allowing investors to trade shares on each other’s platforms, in a move that could significantly widen foreign investors’ access to China equities.

The move is a sign of how the financial centres of Hong Kong and Shanghai, seen as long-term rivals, are finding ways to co-operate as China’s capital markets grapple with how best to open up to intense foreign investor interest.

That has been accelerated in part by the creation last year of the Shanghai free-trade zone, a showcase for China’s financial engagement with the world. Hong Kong Exchanges & Clearing said it had “been in discussions with its mainland Chinese counterparts regarding the potential establishment of mutual market connectivity initiatives”.