Rebecca Lim has worked with Westpac for almost 20 years, having held her current role for 10 years.
She will continue in her capacity until Westpac appoints her replacement. The bank has commenced a global search.
Westpac chief executive Peter King said: “Rebecca has made a significant contribution to Westpac across various senior roles.
“For the past decade as general counsel, Rebecca has played a pivotal role in navigating the company through various legal and regulatory challenges, including BBSW, responsible lending, the royal commission and AUSTRAC.”
