By Matt Scuffham
LONDON (Reuters) - State-backed Royal Bank of Scotland
Bostock, currently RBS's head of restructuring and a former finance director of Abbey National, will take up the position in October, when Van Saun will become chairman and chief executive of Citizens ahead of a planned stock market listing, RBS said on Thursday.
American Van Saun, who has been RBS finance director since 2009, and Bostock have been the two key lieutenants helping Chief Executive Stephen Hester shed around 900 billion pounds of assets from the bank's bloated balance sheet under a five-year turnaround plan.
Bostock worked at RBS between 1992 and 2001, holding a number of senior roles including chief operating officer and group risk director. He re-joined RBS in June 2009 from Santander UK, where he was chief financial officer.
"He has presided over our substantial restructuring program and risk improvements and he will make a great finance director," Hester said in a statement.
RBS said in February it planned to sell 20-25 percent of Citizens through a stock market listing in the next two years after Britain's financial regulator put pressure on the bank to strengthen its capital position.
Van Saun will take over from Ellen Alemany, one of the most high-profile female bankers in the United States, who will retire after five years running the bank. Alemany has been RBS's top earner during that time. RBS's annual report revealed one employee had earned over 5 million pounds last year and industry sources said that was Alemany.
(Editing by Kylie MacLellan and Steve Slater)