The survey of 520 global companies found that 11% of employees resign and move on to another company, after returning home from abroad.
Kevin Cornelius, human capital partner at Ernst and Young, told HR magazine: "Companies must remember that their highly valued employees are highly sought after, so they must have a retention plan in place to prevent them from leaving.
"Keep track of the individual's development while abroad and look at their development so when they come back you can match their needs."
Cornelius added: "It's amazing how many companies don't have a talent management process in place to prevent things like this happening. You're effectively doing nothing to stop your best people moving to your competitors."
The research also found that nearly half of the companies surveyed expect to increase global mobility assignments in emerging markets over the next year.
And it claims global mobility is expected to rise significantly over the next three years.
Stephanie Phizackerley, human capital partner at Ernst and Young, said: "As the global economy remains uncertain many leading companies are directing fresh investment and talent to growth or emerging markets, while simultaneously trying to maintain margin and revenue in mature regions with an experienced workforce and more focused strategies."
She added: "To meet the many challenges that organisations face, it is essential that talent management and global mobility are integrated to make sure that expertise and experience are exploited to the best advantage."
