More women are being sent on jobs abroad than ever before, but they are far less likely to be accompanied by their partner than male counterparts, according to a new report by Mercer Human Resource Consulting.

The global survey covers more than 100 multinational companies with nearly 17,000 male and female international assignees.

Companies in Asia-Pacific said they have 16 times more females on assignment this year than they did in 2001. Those in North America have nearly four times as many while those in Europe have over twice as many.

"The huge growth in the number of females sent on assignment by Asia-Pacific companies reflects the fact that businesses in this region, particularly in China, are becoming increasingly global," said Yvonne Sonsino, principal at Mercer Human Resource Consulting.

Over half of the companies (55 per cent) expect the number of female assignees to continue to increase steadily over the next five years, while 35 per cent believe the number will remain the same. Just four per cent believe it will decline.

"Going on expatriate placements can be an important step on the career ladder, and women are increasingly interested in taking these assignments. Yet many companies' policies are outdated and do not reflect the changing profile of their expatriates, so assignees' requirements are dealt with on a case-by-case basis," said Ms Sonsino.

Though the companies surveyed generally do not have separate policies for female expatriates, the study found some differentiation in the treatment of male and female assignees. For example, 15 per cent of companies said they would not send women to hardship locations such as the Middle East.

Female expatriates are more likely than males to leave their partners at home when on assignment. While 57 per cent of companies said the majority of their male assignees are accompanied by a partner, just 16 per cent said most of their female expatriates are.

Female expatriates are also less likely than their male counterparts to have a partner prior to going on assignment. While 74 per cent of companies said the majority of their male assignees had partners beforehand, only 25 per cent said this was the case amongst female expatriates.

"Studies suggest partners of successful women also tend to have high-powered careers. When a woman is offered an international assignment, their partner may be less willing to make career concessions to accompany them," said Ms Sonsino. "This may strengthen the need for companies to have well-defined spouse support policies which include assistance for the partner in finding work."

Two-thirds of companies (66 per cent) provide no incentives or support to help partners settle in the host location, the survey found. Where support is available, it is usually only given when specifically requested. For example, only seven per cent of companies offer partners information on the local job market, though 37 per cent said they would provide it if asked.

"An unhappy spouse can often cause an assignment to fail, so not spending money on support services can be a false economy for companies. While integrating partners into the local community may take time and money, it can ultimately pay off," said Ms Sonsino.

In the survey, 12 per cent of companies said they have female expatriates who are single parents, yet only four per cent provide additional support.