Georges Moustaki, the Egyptian-born French singer-songwriter who provided the lyrics for Edith Piaf's international 1958 hit Milord, has died at his home on the French Riviera, aged 79. Famed for his repertoire of simple romantic ballads, Moustaki wrote in the region of 300 songs, many of them performed by a galaxy of much-loved Gallic stars, including Yves Montand, Juliette Greco, Pia Colombo, and Tino Rossi.

After a decade of composing songs for these celebrated artists, Moustaki launched a successful career as a performer himself, singing in French, Italian, English, Greek, Portuguese, Arabic and Spanish.

Moustaki, born Giuseppe Mustacchi in Egypt, was the son of immigrant Jewish parents who had moved from the Greek island of Corfu to Alexandria, where they ran a bookshop.

He would later write: "The Alexandria of my childhood was the world in miniature with all races and all religions. I was rarely a foreigner anywhere because I always found some reference to Alexandria in the languages I heard, the smells I breathed or the colours."

His father, Nessim, spoke five languages; his mother, Sarah, six. At home, the young Giuseppe and his two older sisters spoke Italian, in the streets Arabic, at school French. In his parents' shop he discovered the literature of André Gide, Jean-Paul Sartre and Albert Camus.

At the age of 17, after an idyllic summer holiday in Paris, Moustaki obtained his father's permission to move there, working as a door-to-door salesman of poetry books. After his mother sent his guitar from Egypt, he changed his first name in honour of his hero, the celebrated French singer Georges Brassens, and began playing and singing in nightclubs, where he met some of the era's best-known performers.

"My taste for music came from French songs: Charles Trénet, who dazzled me, and who, a long time afterwards, I told as much; Henri Salvador; Georges Ulmer; Yves Montand; Georges Guétary, Luis Mariano.

"I would borrow my father's long trousers (when young) to go and hear them sing. I even saw Piaf with my mother when I was 13 years old, 10 years before I met her," he said.

Moustaki was introduced to Piaf in the late 1950s by a friend whose praise of the young composer was so flattering that Piaf, then at the height of her fame, asked somewhat sarcastically to hear him sing his best works there and then.

"I picked up a guitar and I was lamentable. But something must have touched her. She asked me to go and see her perform that same evening at Olympia [the Paris music hall] and to show her later the songs I had just massacred."

He soon began writing songs for Piaf, the most famous of which, Milord, about a lower-class girl who falls in love with an aristocratic British traveller, reached number one in Germany in 1960 and went to number 24 in the British charts the same year. It has since been covered by numerous artists, including Bobby Darin and Cher.

Moustaki's relationship with Piaf was not exclusively professional. The two became lovers and embarked on what Libération described as a year of "devastating, mad love", with the newspapers following "the 'scandal' of the 'gigolo' and his dame day after day".

Moustaki achieved fame in France with songs including Le Métèque and Ma Liberté, a hymn to the free spirit of the 1960s, which, with his bushy beard and mop of hair, he seemed to personify. He also wrote film music and loved drawing, painting and, above all, travelling. His singing career ended in 2009, when he complained of a bronchial condition that made it impossible for him to carry on performing.

In a tribute to the singer-songwriter, Juliette Gréco said: "He was an absolutely charming man, a gentleman, a fine man. This was an elegant man with infinite softness, and of course, talent. He was like all poets, there was something different about him."

In December, Moustaki told French radio station RTL that he wanted to be buried in Alexandria, his birthplace. "There is a cemetery that is the cemetery of free thinkers and it is there that I want to rest for eternity," he said.

Moustaki and his wife, Yannick (Annick) Cosannec, had a daughter, Pia, also a singer.

• Georges Moustaki (Giuseppe Mustacchi), singer-songwriter, born 3 May 1934; died 23 May 2013