Ocado, the online service that delivers Waitrose groceries, says it is considering a flotation.
Customers who have spent at least £300 with them this year will be given the chance to buy shares if it goes ahead.
It is the first time Ocado has made a formal statement about selling its shares to the public, although there have been rumours it would float since 2004.
The business, which was set up in 2002, has never made a profit.
Ocado was formed by three ex-Goldman Sachs bankers along with the department chain John Lewis, a sister business of Waitrose.
As well as the founders, current shareholders include the John Lewis pension fund and Proctor and Gamble.
Its last set of accounts show it reduced its annual operating loss to £14.4m, on sales up 25% to £427m.
The company, which does most of its business in the south of the country, says it can deliver to 70% of households.
It recently signed a new 10-year agreement with Waitrose, a deal that was widely interpreted as clearing the way for a flotation.
Tim Steiner, Ocado's chief executive, said it was early days: "Although we haven't made a decision on whether to proceed with the float, there has been lots of media speculation and we have had questions from customers.
"So we wanted to alert them now that it is our intention to offer current customers the chance to buy shares if we go ahead."
Some investment analysts are sceptical about any share issue. Justin Urquhart Stewart of Seven Investment Management said Ocado's lack of a profit was worrying.
"In these days of economic frugality, it's wise to invest in something that makes money, not loses it," he said. "It is a cyclical business, despite what they love to tell us, and these days we're all buying less."