William Donaldson, chairman of the US Securities and Exchange Commission, who was tipped to stand down after the recent presidential election, is understood to have asked to stay on for at least 12 months.

Donaldson is seeking the extension to push through his ambitious regulatory reforms, many of which have yet to be completed, according to senior market officials in New York. Sources close to the SEC said Donaldson was keen to stay on in the job and had plenty of unfinished business.