Hong Kong-listed shares of major financial institutions came under pressure on Friday amid growing concerns that Beijing's tighter capital controls could affect the cross-border wealth management and banking businesses of global financial firms with significant exposure to mainland China.Shares of AIA Group declined more than 3% shortly after the market opened, while HSBC Holdings fell nearly 2%. Standard Chartered dropped around 3%, and Bank of East Asia lost more than 2% as investors reacted to reports of stricter scrutiny on offshore account openings and cross-border fund flows.According to a Reuters report, the selloff followed weakness in London-listed financial stocks overnight after a report by the South China Morning Post indicated that mainland Chinese residents were facing increased restrictions when attempting to open offshore accounts with major Hong Kong banks.The report highlighted that customers seeking to open investment-related accounts were encountering tighter compliance checks, reflecting growing regulatory oversight of cross-border financial activities. It also noted that bank staff were emphasizing the need for funds transferred into investment accounts to comply with Hong Kong's regulatory requirements.Reuters reported that the latest developments come after Chinese authorities tightened capital controls on May 22 and took action against brokers accused of conducting business in mainland China without the necessary licenses. The measures are part of Beijing's broader efforts to strengthen oversight of capital outflows and financial activities involving offshore markets.At the same time, Hong Kong regulators have increased pressure on banks to strengthen due diligence procedures. Financial institutions have been instructed to verify clients' sources of funds more rigorously and to shut down accounts associated with suspicious activity or forged documentation.The tougher regulatory environment has raised concerns among investors that financial firms heavily reliant on wealth management, insurance, and cross-border banking services may face slower business growth. Hong Kong has long served as a key gateway for mainland Chinese investors seeking overseas financial products, making any restrictions on capital movement particularly significant for the city's financial sector.Market participants are now closely monitoring whether the latest regulatory measures will have a lasting impact on cross-border investment flows and the earnings prospects of international banks and insurers operating in Hong Kong and mainland China.