Banthoon Lamsam stepped down as chairman of the board of Kasikornbank (KBank) on Thursday, the bank announced.
The KBank board also decided to appoint Kobkarn Wattanavrangkul, independent vice chairwoman, as acting chairwoman.
If and when Ms Kobkarn's appointment is endorsed by the central bank, she will become the bank's first independent member of the board to take on the role.
Mr Banthoon also quit as a board member.
He will also be succeeded as the bank's chief executive officer by Kattiya Indaravijaya, co-president of KBank. She will be the bank's first female CEO and someone not from the Lamsam family to take up the top post. Her appointment is effective today.