Tucker has spent 25 years working across the company’s UK, US and Asian operations and was appointed to the role in May 2005.
Harvey McGrath, Prudential’s chairman, said: “We are truly sorry to see him go, but fully respect his decision.”
Thiam joined Prudential in March last year from Aviva, where he was an executive director and chief executive of Aviva Europe.
A French national, Thiam began his professional career in 1986 with McKinsey & Company with which he worked in Paris and London.
In 1994 he returned to his birthplace, the Ivory Coast, and was eventually appointed as minister of planning and development, but fled the country after the military coup in 1999.
He was elected as a partner of McKinsey in 2000, where he worked until joining Aviva in 2002.
