The business and financial adviser found 66% of UK privately-held businesses employ women in senior positions, compared with 94% in the Philippines, 88% in Russia and 81% in mainland China.
More than seven out of 10 (71%) privately-held businesses in the UK did not have any initiatives in place to support women who wanted to progress to senior positions.
But more than half (53%) thought women had the same career opportunities as men and only 25% felt there were barriers to introducing women to senior management roles in their organisation.
More than a third (39%) felt equal pay between men and women would be achieved within the next five years - but 22% think there will never be gender pay equality.
Alysoun Stewart, head of entrepreneurial advisory at Grant Thornton, said: "Women in the Far East are continuing to break the proverbial glass ceiling in the corporate world contrary to the commonly held perception that women are not given sufficient opportunity within this region. The cultural and social differences in these economies actually give women greater opportunity than many western economies.
"Women today represent nearly 60% of graduates in the EU and girls are continuing to outperform boys at school and enter the workforce in equal numbers. This talent is currently under-utilised by the UK's privately-held businesses and represents a huge opportunity to strengthen the capability and capacity of senior management."
UK private companies have fewer women in senior roles than their Asian counterparts
The UK is lagging behind Asia when it comes to the number of women in senior management in privately-held businesses, according to Grant Thornton.
