When she started out in the financial industry in Malaysia more than 30 years ago, there were times when Ai Chin Tan was the only woman at the table working on a big deal.

Tan is now the top investment banker at her firm, reflecting a wider shift in Malaysia. At the Kuala Lumpur stock exchange’s 100 biggest companies, 31.4% of board seats are occupied by women, according to the securities commission. At conglomerate Berjaya Corp., all eight board members are women.