Sydney

Commonwealth Bank of Australia (CBA), the country's biggest lender, announced a major board shake-up on Monday as it scrambles to shore up investor support following allegations that it oversaw thousands of breaches of anti-money laundering rules.

But the ouster of a third of the bank's non-executive board, including the first two directors to leave since the allegations were made public on Aug 3, failed to impress shareholders as CBA stock touched 10-month intraday lows on the news.