HONG KONG (Reuters) - A daily investment quota for the Shanghai leg of a stock market scheme linking mainland China and Hong Kong exchanges was exhausted in early afternoon trading on Monday, as international investors piled into relatively undervalued Chinese shares.

The daily investment quota for Shanghai is set at 13 billion yuan (S$2.75 billion) while the aggregate quota is set at 30 billion yuan.

According to stock exchange rules, once the northbound daily quota balance drops to zero, no further buy orders will be accepted for the remainder of the day.

The Stock Connect scheme to let Hong Kong and Shanghai investors buy and sell shares on each other's bourses went live on Monday, the latest step towards opening China's tightly controlled capital markets.