(Adds outlook, details, CEO comments, shares)
AMSTERDAM, July 24 (Reuters) - Randstad, the world's second-largest staffing company, said on Tuesday underlying earnings rose 8 percent in the second quarter, driven by growth in all its key markets, slightly beating market expectations.
Underlying earnings before interest, taxes and amortisation(EBITA) came in at 283 million euros ($331 million). Sales increased 5 percent to 6.02 billion euros.
Analysts polled for Reuters had expected EBITA to rise slightly more than 5 percent to 276 million euros. Sales were expected to increase 3.3 percent to 6.06 billion euros.
Randstad's shares were up 2.4 percent by 0707 GMT.
Randstad, which ranks behind Adecco worldwide, said favourable exchange rates lifted the bottom line by 36 million euros, while operating costs rose 2 percent year-on-year, reflecting investments in its digital strategy.
The trade dispute between the United States, China and the European Union, is causing uncertainty, but not feeding into Randstad's business, which is benefiting from strong demand for staffing services globally.
"Most of our clients are still in a good space, very much in need of people," Randstad chief executive Jacques van den Broek said in an interview. "Then there is the political unrest. Let's hope that doesn't mess too much with the economic stability."
Looking forward, Randstad, said overall volumes in early July indicated a continuation of the Q2 growth rate, while the gross margin was expected to be slightly lower in the third quarter.
It reported a gross margin of 19.8 percent in the most recent three-month period, in line with guidance.
Sales at U.S. jobs site Monster, which it acquired in 2016 for $429 million, fell 16 percent for a second quarter in a row, as the company shifts from a traditional advertising market to online job placement services and social media tools.
"The target is that at some point that offsets the decline to the traditional business," Van den Broek said. "When that will happen? We hope as soon as possible."
Overall sales in North America, picked up slightly to two percent growth, compared to a 1 percent rise in the first quarter. Latin America and Asia were bright spots, contributing to 11 percent sales growth in the rest of the world. (Reporting by Anthony Deutsch; Editing by Subhranshu Sahu and Jane Merriman)