By Steve Slater
LONDON, Dec 11 (Reuters) - Nathan Bostock has proved himself an expert in shrinking bloated banks, yet his retail banking skills are likely to hold the key to whether he lands the top job at Santander's British arm.
RBS, 82 percent owned by the UK taxpayer, has many problems and his departure presents a fresh challenge for Chief Executive Ross McEwan. But his exit could ultimately be more significant for the succession at Santander and in helping speed a planned London stock market listing.
The Scot will return as head of risk and deputy chief executive at Santander's UK arm, which analysts and bankers said looked like setting a clear path to its top UK job once it is spun out and floated.
Santander's current UK Chief Executive Ana Botin has been tipped as a likely successor to her father Emilio, who is the 79-year-old chairman of Santander, leaving a question mark over the top post in Britain.
"This could all be part of a broader succession plan," one recruitment executive said.
The move also continues a strengthening of the Santander UK team ahead of a flotation, which has been under consideration for several years but was delayed by the UK recession and a shift in focus to business lending rather than home loans.
As the UK recovery picks up pace, a float is looking more likely late next year or in 2015.
Bostock, a rugby fan with two sons who lives at a farm in Kent, southeast of London, has kept a low profile and people who have worked with him said he prefers to stay out of the spotlight.
When he appeared before Britain's Public Accounts Committee - a parliamentary body charged with scrutinising state spending - in March 2011 alongside other RBS and Lloyds Banking Group executives, he did not say a word, letting his CEO speak on behalf of RBS.
RBS AND SANTANDER HOMECOMINGS
Bostock prepares thoroughly and is well organised, the people who worked with him said, which made him an ideal person to get rid of 385 billion pounds ($632.5 billion) of assets RBS didn't want. "He gets things done and gets people around him who do too," one said.
Bostock has been at RBS or Santander for most of his working life, but has switched roles and companies several times. He has mostly held risk control, restructuring and senior finance jobs.
The mathematics graduate and trained accountant started at Coopers & Lybrand (now part of PricewaterhouseCoopers ) and spent seven years at Chase Manhattan, since absorbed into JPMorgan Chase (Berlin: CMC.BE - news) , before joining RBS in 1992, where his roles over a decade included risk director.
In 2001 he joined Abbey National, later bought by Santander, where he had roles in retail banking and as finance director, before leaving in 2009 to rejoin RBS.
The two men had set up a unit at Abbey to deal with troubled assets and Hester called on Bostock to do the same at RBS on a far bigger scale as head of restructuring and risk.
His task was to shed its masses of "non-core" assets in commercial real estate, home loans, asset management, project finance and elsewhere.
Bostock had planned to leave RBS in 2011 when another former Santander colleague, Antonio Horta-Osorio, offered him the finance director's job at Lloyds, but canceled that move when CEO Horta-Osorio took time off for illness.
He stayed on and at one stage was odds-on favourite with bookmakers to get the job as RBS CEO when the bank ousted Hester. Instead it picked retail bank boss Ross McEwan, who began in October at the same time Bostock became finance chief.
He was paid about 2.5 million pounds at RBS last year and is likely to get a similar amount at Santander, which paid its previous head of risk 1.8 million.
McEwan, possibly aware he could see Bostock at future CEO roundtables, wished Bostock well: "I look forward to competing with him in the UK market as we strive to better the industry for our customers."