Prime Minister David Cameron has unveiled plans to transform London's East End into one of the "world's great technology centres".
Firms including Google and Facebook are to invest in the East London Tech City, he said in a speech.
He hopes the area, which includes Olympic Park, will challenge California's Silicon Valley as a global hub for technology.
Mr Cameron made his announcement in Shoreditch, east London.
The initiative reflects his plan to create private sector jobs to fill the hole left by public sector spending cuts.
In a speech to businesses and entrepreneurs, Mr Cameron said: "Right now, Silicon Valley is the leading place in the world for hi-tech growth and innovation.
"But there's no reason why it has to be so predominant.
'Creativity and energy'
"Our ambition is to bring together the creativity and energy of Shoreditch and the incredible possibilities of the Olympic Park to help make east London one of the world's great technology centres."
He said the response from international technology firms and venture capitalists to the government's proposals had been "overwhelming".
Firms planning to invest in the area, which will stretch from Old Street to the Olympic Park, include Cisco, Intel and British Telecom.
The Olympic Park Legacy Company will provide office space in the Olympic Park.
Mr Cameron said the government is committed to ensuring the UK can become "the most attractive place in the world" for innovative firms to start up.