ADECCO GROUP AG Robert Jan van de Kraats said the decision was not just saddening after decades of European cooperation, but could have profound economic implications.
If free travel barriers are indeed restored between the European Union and Britain, it will impede not only trade, but also free movement.
"It limits the space in which people have to find work and it limits the space companies have to find people," Van de Kraats said in an interview.
Sectors where staff are already hard to come by, such as information technology and engineering, could see a further tightening.
Shortages are now "filled by international mobility and in the case of Britain that is going to become a lot more complicated. Shortages will be created if they do close the employment market," he said.
"If more European countries drop out, it will limit possibilities for people and companies."
Van de Kraats said Randstad was not taking any immediate steps in response to the referendum outcome, but might have to if the European economy takes a hit from Brexit.
"If this results in serious consequences we will do the same thing we did in 2009 and that means restructuring," he said, referring to the year the company's sales plunged 27 percent due to the financial crisis.
Companies looking to grow in Europe will opt for alternatives to Britain, due to heightened restrictions and limited employment mobility, he said.
Randstad, with nearly 30,000 employees in 39 countries, trails leading competitor Adecco. Randstad had sales of slightly more than 19 billion euros last year.
British recruitment companies Pagegroup and Hays both suffered 20 percent share price falls after the shock vote to quit the EU.
(Reporting By Anthony Deutsch)
