Britain's statistics office has sharply revised up its estimate for the size of the economy at the end of 2021, suggesting its recovery from the COVID-19 pandemic may have been much closer to that of other big countries than previously thought.

The Office for National Statistics (ONS) said on Friday that Britain's economy in the fourth quarter of 2021 was 0.6% larger than in the final quarter of 2019, compared with an earlier estimate that it was 1.2% smaller.

Annual growth for 2021 was revised up by 1.1 percentage points to 8.7%, while the slump caused by 2020's pandemic was revised down to 10.4% from 11%.

"These revisions are mainly because we have richer data from our annual surveys and administrative data, we are now able to measure costs incurred by businesses directly and we can adjust for prices at a far more detailed level," the ONS said.

In its last set of quarterly growth data, the ONS estimated that in the three months to the end of June 2023, Britain's economy was still 0.2% smaller than in the fourth quarter of 2019, the last full quarter before the start of the pandemic.

This left Britain at the bottom of the Group of Seven advanced economies in terms of its recovery from the pandemic.

However, if the upward revision to the size of the economy carries across to the latest data, this would place Britain's recovery well ahead of Germany and just behind France and Italy.

The ONS will publish its full annual set of data revisions, including gross domestic product for 2022, on Oct. 31.

Other countries had not finished revising GDP, so it was not yet possible to have a definitive ranking of their economic performance during and after COVID, the ONS said.

(Reporting by David Milliken, Editing by Kylie MacLellan)