The financial services industry needs to move faster to address a huge gender imbalance in its upper ranks if it wants to retain talent, according to an inaugural report on the topic by consultancy Oliver Wyman.

Only 4% of chief executives and 13% of executive committee members at the world's leading financial institutions in 2013 were women, according to the findings, which considered the number of women on boards and executive committees at more than 150 major financial services companies globally.