UK mobile operator O2 has now disabled 100,000 mobile phones in the crackdown on the trade in stolen handsets.
Last November, the UK's mobile network operators finally went live with a new joint database of stolen phones, which was designed to enable them to share information.
In all, there are approximately 440,000 phones on the joint database, 100,000 of which are from O2 contracts.
Since the introduction of that database, any phone reported stolen or lost has been blocked from use on all networks.
Tuesday's announcement demonstrates the success of that effort -- and the scale of mobile theft in the country. It also coincides with a new government intiative to crack down on such crime.
In a statement, Dave McGlade chief executive of O2 UK, said: "We are absolutely committed to tackling the problem of mobile phone theft. What makes this initiative work is the close coordination and partnership between 02, the government, the police and our industry partners to tackle a problem that many previously thought was intractable.
"There are now nearly half a million stolen handsets on the database and handset crime has fallen dramatically since the introduction of the initiative. We will continue to work cooperatively with these and other parties to continually identify other ways of tackling mobile crime."
Tuesday's announcement coincides with the launch of a Home Office-backed campaign called "Immobilise Phone Crime", aimed at further cracking down on mobile phone theft by coordinating the efforts of the police, the operators and other industry bodies -- such as MICAF (the Mobile Industry Crime Action Forum).
Jack Wraith, chief executive of MICAF, said: "UK mobile phone penetration is now over 70 percent and we rely on mobile phones for both or social and professional lives. We should be able to feel comfortable and safe using our mobiles in public but unfortunately, as the handsets have become more advanced and stylish, they have become more appealing to criminals. With the networks and retailers now rendering any stolen or lost handsets useless this appeal will soon decline."
In 2002, just under a third of all street crime in London involved only the theft of a mobile phone. In a further 21 percent of street crimes in the capital, a mobile phone was among the items taken.
At the launch of the initiative Home Secretary David Blunkett said: "I am very pleased to support this new campaign. Mobile phone users can be confident the police, government and industry are committed to tackling phone theft.
"We introduced a new criminal offence of reprogramming which carries penalties of up to five years in jail. This sends a simple message to thieves: stealing mobile phones is pointless and reprogramming them could land offenders with a hefty prison term."