Gilles Planté and Steve Bellotti will take responsibility for ANZ's international and institutional banking business, following Alex Thursby's decision to leave the bank.Thursby, 53, is to become chief executive of the state-owned National Bank of Abu Dhabi. He will start his new job in July.ANZ nominated "a personal desire to be closer to his family's base in the United Kingdom" as one rationale for Thursby's decision.A chance to become a chief executive before a planned retirement at the age of 60 may be another.While regarded as a credible successor to Mike Smith as CEO of ANZ, Thursby most likely would have had to wait two to three years for that vacancy to emerge.ANZ hired Thursby from Standard Chartered Bank in 2007 to the recreated post of group managing director for Asia-Pacific. He provided energetic leadership in executing the bank's then new vision to rapidly grow its banking franchise in Asia. The bank widened his responsibilities to include institutional banking early last year.ANZ said it will conduct a search for his replacement.