PARIS — The eurozone economy is still expanding, but only feebly, according to a private sector report released on Thursday that provided further confirmation that the region’s fragile expansion was only slightly better than outright stagnation.

The report, based on a survey of purchasing managers this month by Markit Economics, a data analysis firm, showed that output barely edged up in both services and manufacturing.

Markit said its composite output index slipped to 52.8 in August, from 53.8 in July. It was the 14th consecutive month that the figure was above 50, a level that signals expansion, but it was also the weakest showing this year. Markit said the pace was consistent with growth in the eurozone’s gross domestic product of just 0.3 percent.

The economy in the 18-country bloc was already running out of gas in the second quarter, according to a report last week from Eurostat, the European Union’s statistics agency. That report showed that the eurozone economy did not grow at all in the April-June quarter from the first three months of the year, as Germany and Italy contracted and France was stagnant.