UPDATE 1-Adecco revenue growth slows in second quarter

(Adds detail, CEO comment, background)

ZURICH, Aug 9 (Reuters) - Adecco reported profit slightly below expectations on Thursday as the staffing company said revenue growth decelerated, hit by slower hiring in many European countries during its second quarter.

The Swiss company, which supplies temporary and permanent workers to industry and offices, said net profit during the three months to the end of June fell 11 percent to 170 million euros ($197.3 million), just missing the average of 173 million euros in a Reuters poll of analysts. It said revenue increased by 4 percent when adjusted for currency effects, acquisitions and working days during June and July, the same as in the second quarter and weaker than the 6 percent rate in the first three months of the year.

Chief Executive Alain Dehaze said general staffing had returned to growth in North America, "mostly offsetting lower growth in certain European countries".

Revenue growth in France -- Adecco's biggest market with nearly a quarter of its sales -- eased from the start of the year, as did the Benelux countries, Italy and Nordic countries, Adecco said.

Concerns about a possible trade war with the United States weighed on European economic growth during the second quarter, which eased to 2.1 percent year on year from 2.5 percent in the first quarter.

Both Randstad and ManpowerGroup -- Adecco's largest staffing rivals -- also reported slowdowns in revenue growth during the second quarter.

Adecco's core operating profit margin fell to 4.3 percent from 4.8 percent a year earlier, indicating increased competition among staffing companies.

($1 = 0.8618 euros) (Reporting by John Revill; Editing by Michael Shields)