LONDON (Reuters) - Britain's economy shrank less than previously thought during the 2008-09 recession, though the downturn remains easily the worst since modern records began in 1948, revisions to official data showed on Tuesday.
British economic output is now estimated at 4.6 percent lower in 2009 than it was in 2007. The decline had been set at 5.2 percent on June 30 and 6.0 percent in the last major annual revision to gross domestic product data, in 2013.
The Office for National Statistics is overhauling how it calculates British GDP in response to new European Union statistical rules and some domestic changes, and publishing regular updates. Further revisions - including quarterly data and figures covering 2010-2012 - are due on Sept. 3.
The main cause of Tuesday's revision was a change in how much Britain's economy was estimated to have contracted as it entered recession in 2008.
The ONS now believes Britain's economy shrank just 0.3 percent in 2008, compared with an estimate of a 1.1 percent decline published only six weeks ago. Last year, it said Britain's economy shrank by 0.8 percent in 2008.
The ONS said the latest change was due to "further quality assurance work" and that the average growth rate in Britain's economy between 1998 and 2009 was unchanged at 2.2 percent.
It had no further details on the exact reason for the change in 2008.
(Reporting by David Milliken; Editing by Larry King)