MADRID/LONDON (Reuters) - Ana Patricia Botin has been schooled for decades to replace her father Emilio Botin at the helm of Santander (>> Banco Santander, S.A.), ensuring that Spain's banking dynasty will remain in charge of the euro zone's biggest bank.

Santander's board of directors unanimously appointed Ana Botin as chairwoman on Wednesday, after her father died of a heart attack at 79, making her the fourth generation of Botins to run the bank.

Botin, who is 53, is an experienced financier in her own right. She has led the British arm of Santander since 2010 and was chairman of Santander's Spanish-based subsidiary Banesto from 2002 to 2010.

She has been on the board of Santander itself since 1989.

Educated in Spain, Switzerland, Britain and the United States, Harvard Business School graduate Ana Botin has a polished international profile and is the only one of Botin's six children to have a major role in the banking business.

A sports fan like her father, she represents Santander at the Davos World Economic Forum and has rubbed shoulders with the likes of David Cameron at the UK Prime Minister's country house retreat, Chequers.

She has quickly made her mark in British banking.

Britain's finance minister George Osborne praised her leadership of Santander's business in Britain when he expressed sympathy for the Botin family following her father's death.

"She has provided strong and stable leadership at Santander UK through a vital period for the UK economy," Osborne said. "I have particularly valued her commitment to supporting enterprise and the small businesses that are the lifeblood of our economy.”

Botin, who speaks five languages, has overseen a big shift in strategy at the UK business, cutting lending to home owners but increasing corporate lending and personal current accounts ahead of a long-mooted flotation.

That restructuring is now regarded as complete and Botin was expected to float the British arm next year. The business contributed higher profits than any other country to the group in the first half of 2014.

"What will be Britain's loss will be Spain's gain," said Mark Garnier, a British politician who sits on the Treasury Committee which often grills top bankers over regulatory issues.

"She's clearly on top of her brief and she has a presence about her that makes her stand out. Her contribution has been a positive one in contrast to a lot of the negative issues that have been around many of the banks."

But Botin, who regularly tops "most powerful women" lists, will also be under pressure from day one to prove herself worthy to follow in her father's footsteps.

"The key issue is whether or not family control is a good or a bad thing. Ultimately this depends on individuals and his (Botin's) daughter is a chip off the old block," Philip Saunders, co-head of multi-asset at Investec Asset Management, said.

An avid golfer like her father, she began her banking career at JPMorgan (>> JPMorgan Chase & Co.), where she spent eight years in corporate and investment banking before moving to Santander in 1988 to work on international expansion, specifically in Latin America.

She is always impeccably turned out, largely shuns the limelight and is protective of time with her family, leaving one corporate event early so as not to miss dinner with her husband.

But it has not always been a smooth ride for the mother of three. Her stint in the 1990s at Santander's investment and corporate banking division included an expansion into Asian equities trading that had to be mostly reversed after Russia defaulted in 1998, roiling markets.

"(Emilio) Botin has driven her very hard to be 100 percent sure," a former Santander banker, who worked with Ana Botin and still advises the bank at a rival firm, said. "She knows the bank inside out."

Bankers who know her said she had a talent for picking good teams to work with, which could bring a shift in management style after nearly three decades in which Santander has been dominated by Emilio Botin's personality.

"Power will likely be more devolved under Ana and shared with the board and the chief executive officer," one senior Spanish banker, said.

The Botin family owns about 2 percent of Santander.

(This story corrects age of Ana Botin to 53)

(Additional reporting by Jesus Aguado, Writing by Sonya Dowsett; Editing by Julien Toyer and Jane Merriman)

By Sarah White and Steve Slater

Stocks treated in this article : JPMorgan Chase & Co., Banco Santander, S.A.