Securities and Exchange Commission chair Gary Gensler said the US audit regulator has been slow to update its rules, in a speech marking the 20th anniversary of the law that created it.

The Public Company Accounting Oversight Board, created as part of the Sarbanes-Oxley Act, continues to work with interim standards that it was allowed to use from the American Institute of Certified Public Accountants, a professional association whose guidelines and rules are often used as fallbacks for the industry.