Alex McLeish resigned as the manager of Birmingham City on Sunday following their relegation from the Premier League, with the club saying he had told acting chairman Peter Pannu in an e-mail he was leaving the Midlands side.
"Birmingham City Football Club can confirm Alex McLeish has resigned as manager," said a statement on the club's website.
"Acting chairman Peter Pannu received an e-mail resignation from McLeish earlier today (Sunday) while away on business in Amsterdam."
"No further comment will be made at this moment in time and updates will be released in due course," the statement added.
Former Rangers manager McLeish was immediately linked with a move to Birmingham's city rivals Aston Villa, still in the Premier League but without a manager following the resignation through ill-health of former France and Liverpool boss Gerard Houllier.
Birmingham were relegated on a see-saw final day of the season last month when a 2-1 defeat by Tottenham Hotspur, combined with other results, condemned them to a bottom three finish.