Prudential announced last month that it planned to buy American International Assurance (AIA) for $35.5 billion in a record-breaking takeover, scuppering a planned listing. It still needs to complete a $21 billion rights issue to fund the deal.
Devey, who joined Britain's largest insurer in 2009, will report directly to Chief Executive Tidjane Thiam and takes up the role with immediate effect, the company said on Wednesday.
A former HBOS banker and managing director at Lloyds Banking Group
His challenge this time will be to combine the two largest foreign players in Asia, with both often operating in the same countries but with different products and different customers.
Difficulties will include dealing with regulatory hurdles and overcoming unease among AIA staff over the deal.
Several analysts have said integration would be an uphill battle, not least because it is the sale of AIA by AIG to an archrival to repay the parent company's loans.
Two senior AIA executives resigned last month and speculation is rife over who will lead the combined group in Asia. Pru's Asian boss Barry Stowe is currently a front runner, but could be replaced by AIA boss Mark Wilson [ID:nTOE63007W].
Devey will continue to be responsible for Prudential UK and Europe but Andrew Crossley, managing director finance, and Barry O'Dwyer, managing director for retail life and pensions, will provide back up, becoming deputy chief executives at the unit.
Analysts said Devey -- likely to be backed by Stowe -- was unlikely to return to his previous full-time position after an integration project which could take around two years.
They said the move by a key UK manager illustrated Pru's refocusing of its operations away from its domestic market.
This move also highlights the increased importance of Asia to the group compared to the UK and may increase speculation that ultimately the UK is non-core and may be disposed or de-merged, analysts at Oriel Securities said.
We would not expect such a decision to be taken in the short term as the UK still generates significant part of the cashflow of the group and effectively funds much of the dividend.
Shares in Britain's largest insurer were up 0.5 percent at 574.5p at around 0800 GMT, above a broadly flat European insurance sector <.SXIP> but in line with the FTSE index.
(Reporting by Paul Hoskins and Clara Ferreira-Marques; Editing by David Cowell)