China Construction Bank's A shares, which gained 32.6 per cent in their trading debut on Tuesday, gained a further 8.6 per cent to 9.30 yuan yesterday.
The stock was boosted by news that the bank may acquire a stake in Bear Stearns, along with other potential investors such as Warren Buffett, the world's second-richest man.
The H shares of the bank, the country's third-largest lender, gained 0.14 per cent to HK$7.11 yesterday.
It was the fifth-most active stock with 460 million shares changing hands.
Bear Stearns, the United States' sixth-largest securities firm, was in talks with several investors, including CCB and Citic Group, interested in buying a 20 per cent stake in the firm, the New York Times reported yesterday, citing an unidentified source.
Hu Changmiao, a Beijing-based spokesman for China Construction Bank, said the bank did not comment on market speculation. 'It was already rumoured last year. We have no knowledge on this issue.'
CCB was rumoured last year to have spent up to US$4 billion to buy part of Bear Stearns. The mainland bank denied the report.