The number of English-speaking teachers working in international schools has topped 300,000 for the first time, with the number expected to grow to more than half a million in the next 10 years, new figures have revealed.
Strong economies, particularly in Asia and the Middle East, have fuelled demand for British and US-style education, leading to a rise in the number of international schools overseas.
The UK is the biggest single supplier of staff to the sector, accounting for more than 100,000 teachers.
The numbers were released by ISC Research, a body that tracks international schools and is part of the International School Consultancy Group. It says the number of such schools has more than doubled to 6,400 since 2000.
Britain's education system is seen as a lucrative export: the education sector overall, including universities, is said to be worth up to #163;15 billion a year to the UK economy.
According to ISC Research, the demand for English-speaking schools abroad will cause the number almost to double again to some 11,300 by 2022, employing a predicted 529,000 teachers and teaching about 6 million students. Based on annual fee income, the international school market is bringing in #163;20.8 billion a year, with that figure expected to rise to #163;30 billion in 10 years' time.
UK independents are tapping into this lucrative market, with Harrow School, Wellington College and Marlborough College having opened campuses in Asia and the Middle East.
But some of the larger international school providers are concerned that the rapid expansion of the market is making it hard for the supply of English-speaking teachers to keep up with demand.
Clive Pierrepont, director of communications at Taaleem, one of the largest international school providers in the Middle East, said firms such as his needed to sell the benefits of life abroad even more to try to attract the best teachers.
"The supply of teachers is definitely more challenging as a result of the growth in the market, especially for the cream of the crop such as qualified, experienced International Baccalaureate and British teachers," he said.
Top 10 countries by number of international schools:
378 - UAE
346 - Pakistan
342 - China
320 - India
222 - Japan
181 - Saudi Arabia
174 - Indonesia
168 - Hong Kong
164 - Thailand
119 - Qatar.