Spanish writer Javier Marias, whose work has been translated into more than 40 languages in nearly 60 countries, died Sunday in Madrid at the age of 70 after suffering from pneumonia, his publisher said.

"With enormous sadness, in our name and on behalf of the family, we regret to announce that our great author and friend Javier Marias passed away this afternoon in Madrid," Alfaguara said in a statement.

The statement said he had been suffering "for several weeks from pneumonia which worsened in recent hours".

The El Mundo daily said the pneumonia was "caused by Covid-19" and that the author had been hospitalised for months.

Born in Madrid on September 20, 1951, the Madrid-based author, considered one of the great authors of contemporary Spanish literature, published his 16th novel Tomas Nevinson last year.

His best-known works include "All Souls" (1989), "A Heart so White" (1993), which brought him critical acclaim, and "Tomorrow in the Battle Think on Me".

A member of the Royal Spanish Academy of Language since 2008, Javier Marias spoke fluent French and English.

A passionate filmmaker and Real Madrid fan, he was also, despite republican principles, the ruler of the fictional kingdom of Redonda -- an uninhabited islet in the Lesser Antilles.

According to El Pais daily, he underwent an operation on his back shortly before the coronavirus pandemic.