An El Corte Inglés spokesperson announced on Wednesday that 79-year-old Alvarez had been taken to Puerta de Hierro de Majadahonga University hospital in Madrid after suffering respiratory problems.
El Corte Inglés is one of Spain's most prestigious retail groups and Álvarez is an important figure in the business community but the story was overshadowed by the news that Santander Group president Emilio Botín had suffered a fatal heart attack.
National media were still discussing the death of Botín, and the appointment of his daughter as his successor at Spain's biggest bank, when news broke that a third business leader had been hospitalized.
65-year-old Josep Oliu, who heads one of Catalonia's top banks, was taken to hospital in Barcelona after falling from a horse.
X-rays showed that he had broken his collarbone and several ribs but hospital reports indicated that he had avoided serious injury.