The insurer had lined up non-executive director Sir Win Bischoff to replace Clementi this summer but Bischoff was appointed chairman of Citigroup late last year.
Prudential is thought to have drawn up a list of between six and 10 candidates but no interviews have been held.
It is believed that only people from outside the company are being considered.
Clementi, 59, has been chairman since December 2002 but is seen as lacking the international experience that Prudential needs as it expands globally.
It is understood that senior independent director James Ross has been ruled out of the running.