Debenhams has said its finance director Simon Herrick had quit, two days after the British retailer issued a sharp profit warning due to poor Christmas trading.
Mr Herrick, who had held the role for two years, was already under fire after he asked suppliers for a discount and a one-off contribution in the days running up to the key festive period, according to local reports.
The company said a search to find a replacement was underway.
Whoever takes the job will be tasked with rebuilding confidence among investors after the group issued its second profit warning in less than a year.
Its shares are down almost 40% in the last 12 months.
In the downgrade delivered on Tuesday, it cut its first-half profit forecast by almost 25% after the hoped-for surge in last-minute Christmas shopping failed to materialise.
Debenhams, Britain's second-largest department store group, attributed the latest warning to fierce discounting on the high street, but the group was already struggling as it failed to keep up with rivals John Lewis, House of Fraser and Next.
John Lewis, the employee-owned biggest department store, reported like-for-like sales up 6.9% in the five weeks to 28 December, while House of Fraser sales were up 7.3% in the last three weeks.
Neil Kennedy, director of finance, will assume the role of acting chief financial officer at Debenhams on an interim basis.