LONDON: The latest Markit/CIPS service sector purchasing managers’ index (PMI) fell to 55.6 last month from 57.4 in July.
Although the figure remained above 50, indicating expansion, it was the weakest reading since May 2013.
Markit estimated the UK economy would grow by 0.5% in the third quarter of 2015, down from growth of 0.7% in the previous three months.
Earlier this week, a survey of the manufacturing sector also found growth slowing, although the construction sector recorded a slight pick-up in activity.
“Even after allowing for usual seasonal influences, August saw an unexpectedly sharp slowing in the pace of economic growth,” said Chris Williamson, chief economist at Markit.
“The services PMI came in well below even the most pessimistic of economists’ forecasts and follows disappointing news of a stagnation in the manufacturing sector earlier in the week.”
The Markit survey said the slowdown in the sector was mainly due to the slowest increase in new business since April 2013.
