The Swiss company said net profit fell 29 percent to 123 million euros (108.46 million pounds), missing forecasts of 212 million euros in a Reuters poll.

Adecco said its results had been hit by a 129 million euro non-cash charge for a write-down in the value of trademarks. It said the change reflected a "streamlining" of its brand portfolio, without giving further details.

Adecco operates around the world under several names, including Adia, Badenoch & Clark, Lee Hecht Harrison, Modis, and Yoss. In Japan the company this year started operating its permanent placement business under the name Spring Professional.

When the write-down was removed, Adecco's earnings before interest and tax (EBITA) reached 321 million euros, level with a year earlier and in line with forecasts of 319 million euros.

Sales for the three months ended Sept. 30 rose 2 percent to 5.9 billion euros, missing forecasts of 6.01 billion euros.

When currency swings and changes in working days were taken into account, Adecco's revenues grew 6 percent in the quarter - the same growth as the previous three months, with strong growth in France, Italy, Spain, Belgium and the Netherlands.

Adecco said there had been an acceleration of its revenue growth to 8 percent in September.

"Positive momentum continued at the start of Q4 2017, but the comparison base is more challenging this quarter," the company said.

Staffing companies are benefiting from a positive economic environment where companies prefer to hire staff on a flexible basis while they remain unsure about the solidity of the global economic recovery.

For the third quarter, Adecco's revenue rose 6 percent in France, its largest market, where it has been hoping for an upswing from labour market reforms unveiled by President Emmanuel Macron, including talks this week on how to reform its apprentice system.

But Britain and North America remained tough, with general staffing revenues down 5 percent and revenues from placing professional staff down 10 percent.

Staffing companies are seen as a bellwether for the health of the wider economy, with employers often taking on temporary workers at the start of a recovery before switching to permanent staff.

(Reporting by John Revill; Editing by John Miller and Stephen Coates)