Ana Patricia Botin, the boss’s daughter, has come to the U.K., where she will have the chance to prove she can lead the bank in Spain that her family has run for more than six decades.

Ana Patricia Botin, the boss’s daughter, has come to the U.K., where she will have the chance to prove she can lead the bank in Spain that her family has run for more than six decades.

With her appointment as chief executive officer of Banco Santander SA’s U.K. unit in November, Botin became the most powerful woman in London finance. Now, if she can repair the bank’s customer-service reputation and pull off an initial public offering, she will have improved her odds of succeeding her father, 76-year-old Chairman Emilio Botin, who built Santander into the euro region’s most valuable lender through more than $70 billion of acquisitions.

“What she wanted, she usually got,” said Jose de Ochoa, who worked with Ana Botin expanding Santander in Latin America, including the 1997 purchase of Colombian lender Bancoquia.

London will be the toughest test yet for Botin, 50, whose performance is being closely watched in Spain, where Botins have helped manage Santander for 115 years. She takes charge after former U.K. head Antonio Horta-Osorio defected to lead rival Lloyds Banking Group Plc. An IPO was postponed this year, and Botin will have to explain to investors that Santander’s outlook is solid at a time of doubt about Spain’s banking system, said Simon Maughan, an analyst at MF Global Holdings Ltd. in London.