The CEO is currently guiding the insurance firm through one of the biggest capital right issues ever undertaken to fund the $35.5 billion takeover of AIG's Asian offshoot.
Prudential is hoping to raise up to $21 billion from the issue as part of the deal, which some shareholders have criticised as being too expensive.
A âtopâ Prudential shareholder told the Times that the Mr Thiam's decision to take on another role during this time was âincredibly arrogantâ.
âHe has only just inherited the chief executiveâs job and he has already taken on this huge task of doubling the size of the company. That transaction has yet to get investors on board. Doing this and doing it now just does not make sense,â the unnamed investor explained.
The CEO will be expected to attend a minimum of five three-hour board meetings per year as part of his new post.
Mr Thiam is currently attempting to gain more support for the acquisition across Prudential and has promised to make the venture profitable within three years of its completion.
The deal is expected to be completed by June of this year.
By Jim Ottewill