Surveys of eurozone businesses have revealed growth in July was the weakest in over a year and a half.
The strongest performances were in the two big economies – Germany and to a lesser extent France.
Chris Williamson, chief economist at Markit, which carried out the surveys, said: “There is a strong indication that Italy and Spain saw a deterioration in growth rates.”
There seems to have been some negative impact from Britons voting to leave the European Union, but economists had expected it to be worse.
Positive factors in the eurozone were rising employment – particularly in the services industry – and the weaker euro bolstering exports.
The slight loss of momentum may concern the European Central Bank’s policymakers who have been trying to stimulate faster growth.
Markit said “the fragility of the recovery leaves plenty of room for speculation about further stimulus later in the year.”
“It’s a pretty pleasant surprise that the fall was so muted. It suggests that Brexit is unlikely to trigger the substantial slowdown that many people are predicting,” said Ben May at Oxford Economics.