Tesco, Waitrose and InPost sign up for London Tube click and collect
Three retailers are set to provide click and collect services at Tube stations.
Tesco, Waitrose and InPost are finalising details with Transport for London (TfL) and hope the service will be available in the coming months.
There are also plans to expand a pilot with Asda and talks with Amazon to provide a service are "continuing".
But Matthew Jaffa, of the Federation of Small Businesses, said it was "another nail in the coffin" for shops.
The click and collect service enables customers to place orders online and collect them from stations or station car parks.
Tesco plans to provide collection points at Osterley, Newbury Park, Rayners Lane, Finchley Central, Arnos Grove and Cockfosters.
Waitrose will operate at six stations and InPost, which delivers parcels, will work out of three stations, although the locations are yet to be decided.
Mike Brown, managing director of London Underground, said: "The primary role of our stations must always be travel and we will never compromise that, but there is much more we can and will be doing to improve and modernise our stations."
Robin Phillips, e-commerce director at Waitrose said it would "reach customers in locations where we don't have a shop".
But Mr Jaffa said "bulk buying" was a concern for smaller retailers.
He said: "It's another reason why we might see certain shops suffering, we need to try and make sure that businesses can compete.
"There is a place for online, but we need to ensure there's a balance for shopping online and shopping in the community."
TfL said it was also working with small businesses and recently helped Rockflower open a stall and vending flower kiosk at Blackfriars underground station.