In a surprise announcement, Adecco said its CEO Patrick De Maeseneire would be leaving at the end of August and would be replaced by Alain Dehaze, a Belgian national who currently leads the company's operations in its key
The Zurich-based company also announced that its chief financial officer Dominik de Daniel had decided to leave at the end of July, and that his successor was yet to be determined.
Adecco's board thanked both men for their "outstanding contribution" to the company, but gave no explanations for their departures.
"The fact that the board decided for an internal successor stands for continuity," chairman of the board Rolf Doerig said in a statement of the decision to hand the reins to Dehaze, who joined Adecco in 2009.
Thursday's shake-up announcement cast a shadow over Adecco's stellar earnings, which showed a 45-percent jump in net profit in the first quarter to €160 million ($182 million).
That was better than the expectations of analysts polled by the AWP financial news agency, who had anticipated a net profit of €145 million for the quarter.
Adecco's revenues meanwhile grew nine percent to 5.0 billion euros as the economic outlook improved in Europe.
"In the first quarter revenue growth accelerated, helped by an improving environment in Europe," De Maeseneire said in the earnings statement.
"Conditions in France stabilized and we saw a pick-up in Benelux, while Italy, Iberia and Eastern Europe again achieved double-digit growth," he said.
France meanwhile lost its place as Adecco's largest market, with North America taking the lead for the quarter with 21 percent of total sales.
In France, which accounted for a fifth of Adecco's total sales, revenues slipped two percent during the quarter to €1.0 billion, hit by a weak construction sector.
Looking forward, the group said that based on the current economic outlook, it expects "revenue growth to accelerate in the second half of 2015".