The first companies to use the .london web address, set to go live at the end of this month, will include West Ham United football club, Fortnum & Mason and the London Symphony Orchestra.
Business leaders from across the capital came together today to show their support for the new Dot London domain two weeks ahead of its launch on 29 April.
"For the first time in a generation London businesses have an opportunity to claim a web address that associates them with London and make their web address more relevant and memorable," businesses and organisations adopting the domain said in an open letter published today.
More than 200,000 London businesses indicated through a YouGov poll in January that they would be interested in adopting the new address, one of the first city-based domains to be launched.
Berlin introduced its "dot berlin" domain name back in March.
Karen Brady, vice chairman of West Ham United, said: "As the traditional London Club, with roots formed at the heart of the East End in 1895, a move to become the first football club to use the Dot London domain is a natural fit for West Ham United."
Mayor of London Boris Johnson said that interest has come from both major high street brands and small local businesses.
"London leads the world in technology and our businesses are among the most dynamic and innovative anywhere so it is no surprise that so many see Dot London for the great opportunity it presents them," Johnson said.
The new .london address is part of a major domain name expansion that will see global internet body ICANN release more than 1,000 new internet domains this year.