Based in London, the system will include input from GCHQ, the government communications body, the MI5 counter-intelligence and security agency, police and businesses -- and will work through a secure web-portal to allow access to shared information in real time, like a "secure Facebook," officials said.
Attacks on British computer networks by other countries, criminals and companies seeking sensitive information have cost the economy billions of dollars, they said.
"No one has full visibility on cyberspace threats," a government official told the BBC. "We see volumes of attack increase and we expect it to continue to rise."
Almost 200 British companies from five sectors of the economy -- finance, defense, energy, telecommunications and pharmaceuticals -- have joined the initiative, dubbed the Cyber Security Information Sharing Partnership, the BBC said.
The kinds of information to be shared will include technical details of an attack, methods used in planning it and how to mitigate and deal with one.
"This innovative partnership is breaking new ground through a truly collaborative partnership for sharing information on threats and to protect United Kingdom interests in cyberspace," Cabinet Office minister Francis Maude said.