The study found men on average earn £141,500 more in bonuses than women doing the same role over the course of a working lifetime.
The CMI said male salaries were already almost 25% higher than female salaries before bonuses are taken into account.
CMI's analysis of the National Management Salary Survey, which includes data from more than 43,000 workers, showed men took home bonuses worth £6,442 in 2012, compared to £3,029 for women.
The gender bonus gap is even more pronounced at senior level, with female directors earning an average bonus of £36,270, compared to male directors' £63,700.
Pay gap widening
Yvette Cooper, shadow minister for women and equalities, called the findings "disgraceful".
"The corporate gender pay gap seems to be getting wider rather than narrowing," said Cooper.
"It is in the interests of business and the economy for women's talents to be valued and promoted. And it's high time that women were fairly rewarded. Instead, once again, it looks like the clock is being turned back."
The study found even without taking bonuses into account the gender pay gap still increases with each rung of the management ladder.
At entry level women earn £989 more than men on average, but by middle management they receive £1,760 less than men director level the gap widens to £15,561.
Losing ground
Ann Francke, CMI chief executive, said: "Despite genuine efforts to get more women onto boards, it's disappointing to find that not only has progress stalled, but women are losing ground at senior levels.
"Women are the majority of the workforce at entry level but still lose out on top positions and top pay. The time has come to tackle this situation more systematically."
The research also showed despite women being the majority in entry-level roles and more women embarking on executive careers, fewer than a quarter of board directors are female.
In 2011 Lord Davies conducted a review into gender balance on company boards and set a target of 25% by 2015. However, in May there was the first recorded fall in the percentage of women on boards.
