Spanish banking magnate Emilio Botin, who built the country's Banco Santander into a global financial giant and was widely seen as the nation's most influential business leader, has died of a heart attack, the company said Wednesday. He was 79.

Born into a family of bankers, Botin was known for his hands-on leadership of Banco Santander. He turned the institution previously run by his father into Spain's biggest and then into the eurozone's largest by market capitalization through a series of acquisitions. He also transformed it into a major bank in Latin America.

Botin was known for visiting bank branches to meet with employees and had influence in political circles in Spain and abroad, rubbing shoulders frequently with Spain's royalty and prime ministers and Latin American heads of state. He didn't hesitate, however, to criticize government economic policies in the media when he disagreed with them.

Bank parent company Grupo Santander said in a statement that its board will meet Wednesday to name Botin's successor as chairman.

A bank spokeswoman said he died Tuesday night after suffering a heart attack at his home. She spoke on condition of anonymity because of company rules preventing her from being named.

The bank's 10 main markets are in Spain, Brazil, Britain, Mexico, Portugal, Germany, Chile, Argentina, Poland and the United States. It has 102 million customers and more than 186,000 employees.

Botin and 11 relatives were investigated in 2011 for possible income and wealth tax evasion focusing on accounts the family held in Switzerland, but Spain's National Court dropped the probe in 2012.

The Botin family's lawyers said the accounts stemmed from assets Botin's father held outside Spain when he died and that about 200 million euros ($259 million) in back taxes were paid to normalize the situation.

Santander's shares were down 1.5 percent in midday trading in Madrid on Wednesday while Spain's main stock index slipped 0.7 percent.