The luxury goods retailer joins a list of high-profile users that includes Marks & Spencer and Tesco. Analysts said the move shows the increasing acceptance of .net among UK companies, particularly large retailers.
Harrods, which is launching a revamped version of its www.harrods.com site this week, said its long-term strategy is to sell as many of the store's 700,000 products online as possible, using .net technology.
"Our long-term objective is to enable customers to buy online whatever they could ordinarily purchase when physically in the store," said Rob Bowyer, Internet systems manager at Harrods.
"Our sales have doubled since we launched last June and we hope they will quadruple within two years," he said.
Harrods outsourced the running of its Web site to services provider Attenda - a .net specialist - three months ago. The store has already used the Web services technology both externally and internally, Bowyer said.
"Our first .net service for the Web site is an application that links to a partner site allowing users to view their transaction history," he said. "As far as the user is concerned it is an extension of the Harrods site but it is, in fact, run by a third party. And because it is .net the link is quick and invisible."
Using .net has also enabled Harrods to implement a company intranet - something it has always shied away from because of the time it would have taken to roll out, Bowyer said.
"One of the main advantages of using .net is the rapid application development it allows," he said. "We were able to get the intranet up and running in a matter of days, something that was just not possible before."
Bolo Rotibi, a software development analyst at research firm Ovum, said more companies are likely to implement .net in the coming months.
"This shows that people are ready to use this technology and more and more are likely to do so - particularly those with a Microsoft-based infrastructure," she said. "The fact that Harrods was able to create applications quickly shows that migration to .net can be quick."
Harrods online customers can expect to see a wider range of food on offer and some bigger-ticket items such as furniture on the site in future, Bowyer said.
The company is also considering interactive TV services, he added. "We had a dabble with Open [Sky's early iTV service] and that was successful so it is something we are definitely looking at," he said.