New Delhi: The number of 'global nomads', employees who move from country to country on multiple assignments, has increased significantly over the last three years causing challenges for employers when it comes to providing expatriate benefits, says a survey.

According to Mercer's 2011/2012 Benefits Survey for Expatriates and Internationally Mobile Employees, which provides an overview of expatriate policies within large multinational companies, provision of expatriate benefits remains a key priority for multinational companies.

Around 85 percent of multinationals have implemented procedures to monitor success of expatriate benefit policy, while 53 percent of companies have seen international medical plan premium increases of 6 per cent or more.

While percentage of short-term expatriates (those assigned to a project for less than a year) has fallen from 17 percent to 11 percent, long-term expatriates as a percentage of the total assignee population increased from 21 percent to 40 percent between the 2008-09 and 2011-12, Mercer said.

"We are seeing that multinationals are expecting their talent pool to have varied geographical experience as a prerequisite to climbing the top rungs of the career ladder," Mercer's Asia Pacific Global Mobility COE Leader for Information Product Solutions Phil Stanley said.

According to the report, the need to develop global leadership talent and the growth of new business ventures abroad has prompted a rise in global mobility.

"Seasoned professionals who can bring solid international experience and a depth of knowledge across a number of operating environments are vital to companies looking to create or expand new ventures abroad and gain a competitive advantage," Stanley said.

The survey results show that only 12 per cent of companies have established international retirement plans to ensure continuity of benefits.

Employers are also facing challenges to provide expatriates with a broadly equitable system of healthcare whilst managing costs as the quality and standards of medical healthcare vary significantly from country to country.

Nearly all (98 per cent) respondents currently provide private medical insurance for their globally mobile workforce compared to only 57 per cent in 2005.

"An international medical plan provides equality among expatriates and reduces administration effort and time resource constraints. But challenges remain, particularly around costs," Stanley said. The report said that 20 per cent of companies saw their premium increasing between 11-15 per cent.