LONDON - The British economy contracted at a much sharper pace than initially thought and at its fastest rate in more than 50 years in the first three months of this year, official data showed on Tuesday.

The Office for National Statistics said GDP fell by 2.4 percent in the three months to March compared with an earlier estimate for a fall of 1.9 percent. That was the biggest rate of decline since the second quarter of 1958 and worse than analysts' predictions for a fall of 2.1 percent.

GDP fell 4.9 percent compared with a year ago, the biggest decline on record. The previous estimate had been a fall of 4.1 percent.

The extremely large revisions were a result of changes to the methodology of calculating construction output and also lower services output, which each contributed around half of the downgrade.

The data also showed GDP fell in the second quarter of 2008, meaning the recession started earlier. Separately, the ONS released data on the balance of payments. The current account recorded a deficit of 8.540 billion pounds.