More than 11,500 staff at Marks & Spencer are in line for a post-Christmas windfall averaging £3,500.
Payouts totalling £40 million are due to be made from three M&S incentive schemes after the share price of the retailer rocketed to around 500p in recent weeks.
Staff who saved the maximum amount of £250 per month in a five-year scheme starting in 2000 could make a
gain of £39,085 at the current share price, representing a return of 260 per cent on their original investment.
M&S, headed by chief executive Stuart Rose, also operates a seven-year Sharesave scheme and one lasting three years. Both are due to mature this month.
Mr Rose said: "We are delighted that many of our employees who have shown their faith in our business are able to reap the benefits of their hard work."
More than 22,000 M&S employees are scheme members, They save on a monthly basis and use their savings plus a bonus to buy shares at a 20 per cent discount.
M&S is due to update the market on Christmas trading tomorrow, with investment bank Morgan Stanley fore-casting a 3.4 per cent increase in like-for-like sales.