The number of employees on international assignments has doubled over the last three years as part of the continuing trends towards globalisation, according to research by consulting firm Mercer.

A rise in expatriate employees is typically beneficial for offshore banking and private client services, as it will mean a growing number of high net worth individuals with specialist wealth management needs.

Mercer’s 2008/09 Benefits Survey for Expatriates and Globally Mobile Employees covers 243 companies worldwide, including 94,000 expatriate employees.  The survey is carried out every three years to provide an overview of expatriate policy in large, multi-national firms and is the most extensive of its kind.

According to Mercer’s report, 47 per cent of companies surveyed said they had increased the deployment of what are considered “traditional” expatriates - employees on 1-5 year assignments.  It also emerged that 38 per cent of companies reported an increase in “global nomads”, employees who continuously move from country to country on multiple assignments.

The growth has been driven by companies' desire to be globally competitive. "To successfully launch new ventures abroad and gain advantage over competitors, companies generally bring in their own experts from other locations to lead projects on a short term basis, rather than rely on local talent," said Robert Lockley, principal in Mercer's international business.

"Increasingly these are corporate global nomads, seasoned professionals who move from project to project within the same multinational company. They bring solid experience in transferring knowledge, and a consistent approach," Mr Lockley said.  He added: "Multinationals highlight that international assignments are part of their global leadership development programmes."

Gaining experience in various geographies is becoming an essential step on the career ladder of international firms. The rising numbers of expatriate employees is driving large multinationals to develop their human resources policies so that they can offer packages which are tailor-made for a mobile workforce, particularly with regards retirement plans. The majority of firms that participated in Mercer’s survey kept their expatriate employees in host or home country retirement schemes.

However, 32 per cent of companies said that they offer international plans, such as offshore plans financed via a trust or insurance contract in an offshore tax sheltered location. This increase represents a rise of close to 40 per cent in comparison to the results of Mercer’s 2005/06 survey.

"More expatriates are going on multiple assignments across several geographies. Over time it becomes difficult for companies to justify the link to the office in the expatriates' original home location when they have not worked there for many years. Also, swapping an employee from host scheme to host scheme is often an unattractive option," said Mr Lockley.