Political and economic uncertainty dampened euro zone private sector business activity in June, a closely watched survey showed today.

Data monitoring company Markit did not cite Britain's EU referendum as the specific cause of the downturn but the vote has roiled sentiment already hit by concerns over the outlook for the US and Chinese economies. 

Markit said its June Composite Purchasing Managers Index (PMI) fell to 52.8 points, a 17-month low, from 53.1 in May.

The PMI measures companies' readiness to spend on their business and so gives a good idea of how the underlying economy is performing. 

Any reading above the boom-bust 50 points line indicates the economy is expanding. 

Markit said the June figures rounded "off the worst calendar quarter since the fourth quarter of 2014 amid signs of political and economic uncertainty dampening business activity." 

Markit's chief economist Chris Williamson said the outcome pointed "to steady though disappointingly lacklustre economic growth."

"Rising political uncertainty appears to have caused the pace of expansion to weaken slightly and business confidence about the outlook to deteriorate," Williamson said. 

The euro zone economy would likely grow just 0.3% in the three months to June, down from 0.6% in the first quarter, he added.