There was a "welcome rebound" for the dominant service sector of the UK economy last month, part-driven by improved weather.
The Markit/CIPS purchasing managers index (PMI) for services activity, in which a reading above 50 represents growth, came in at 53.7 in August, up from 51.0 the previous month, its highest reading since March.
The survey, released early after it was accidentally published, follows a disappointing construction report and improved data for the manufacturing sector.
New contract wins, marketing and the return of some sunshine were all positive factors in the performance, the closely-watched report suggested.
Chris Williamson, chief economist at Markit, said it would add to hopes that the economy will pull out of recession following the 0.5% contraction in GDP seen in the second quarter.
The figure will also probably reinforce the view that the Bank of England is set to hold back from unleashing additional emergency support for the economy on Thursday when it announces its interest rate and asset purchase decisions.
The survey found that new business volumes in the sector, which includes restaurants and financial services, continued to rise for the 20th month in a row though the London Olympics has a mixed effect.
Some panellists reported a positive impact on activity, while others suggested that the Games impaired growth either through travel restrictions in and around London or business generally being put on hold during the period of the Games.
Staffing levels were also found to have increased for a ninth successive month.