The Securities and Exchange Commission has extended the deadline for public companies to participate in its Web-based survey about the costs and benefits of Section 404 of the Sarbanes-Oxley Act.

The voluntary survey is open to any company with Section 404 compliance experience in the U.S. and globally. The deadline has been extended to Jan. 31.

Under a delay approved by the Commission in June 2008, smaller companies are scheduled to begin complying with Section 404(b), which requires an independent audit of their internal controls over financial reporting, at the end of this year. The cost-benefit study was one of the reasons given for the additional delay.

The Commission says the study will help it assess the effects of measures taken by it and the Public Company Accounting Oversight Board to make the Section 404(b) auditor attestation process more efficient, whether the measures have helped companies reduce their compliance costs and whether the Commission should consider additional measures.

The SEC says more than 2,000 companies have already completed the survey.