GENEVA (AFP) - Legendary French-Armenian singer Charles Aznavour, 90, has been hospitalised for an infection and has postponed a concert due to be held later on Friday in Geneva, organisers said.

Dubbed "France's Frank Sinatra," Aznavour is one of the country's best-known and beloved singers, whose ballads are recognised the world over.

"Charles Aznavour has been preventively hospitalised after contracting an infection in recent days," the Opus One event managers said in a statement, without providing more details about his condition or which country or hospital he was being treated in.

The activist-singer's planned concert in Geneva on Friday evening had been postponed, but he and the organisers would try to reschedule the concert "as soon as possible," the statement said.

Aznavour lives in Switzerland, having built a lakeside house near Lausanne to be closer to his youngest son Nicolas, a scientist at the Swiss Federal Institute of Technology in the city.

Aznavour, who began performing at the age of nine, has penned nearly 1,000 songs over his career. "Everything interests me, really everything... I read every day. I have three books: a book I have to read, a book where I learn something and I have foreign language texts that I work on regularly," he told Swiss public broadcaster RTS at the weekend.

"Over the past two months we have travelled to 10 capitals," he said, insisting though that it was not a farewell tour.

"I'll be back next time," he told the broadcaster.