Business growth in the eurozone fell last month and was the weakest since early last year.
Companies responding to the surveys used to compile the Purchasing Managers’ Index (PMI) said they were spending less.
They are cautious about the economic outlook and political uncertainty from the Brexit vote and as Germany and France face elections.
Analyst Apolline Menut at Barclays said: “Anecdotal evidence suggests that economic and political uncertainty is weighing on euro area confidence, and we expect sentiment to be further dampened in the coming month as Brexit negotiations kick in.”
Markit’s final composite Purchasing Managers’ Index for the eurozone was 52.6 in September, matching a flash estimate but below August’s 52.9 and marking a low since January 2015.
It has been above the 50 mark that divides growth from contraction since mid-2013.
In Germany the services sector showed no improvement, highlighting the risk of a slowdown in Europe’s biggest economy in the second half of the year.
Of the biggest four economies in the currency bloc only France showed improvement, with services activity expanding in September at the fastest pace in 15 months as demand improved.
Services PMIs for both Spain and Italy also slipped