Pioneering science fiction writer and visionary Sir Arthur C Clarke died on Wednesday in Sri Lanka at age 90.

He died of heart failure caused by the post-polio syndrome that had kept him wheelchair-bound for years, his personal secretary, Rohan de Silva said.

Marking his ``90th orbit of the sun'' in December, the prolific British-born author and theorist made three birthday wishes: For contact to be made with extraterrestrial life, for humankind to kick its oil habit and for peace in Sri Lanka.

Clarke, best known for his novel ``2001: A Space Odyssey'' and collaboration on the accompanying film classic, was born in England on December 16, 1917, and served as a radar specialist in the Royal Air Force during World War Two.

He was one of the first to suggest the use of satellites orbiting the Earth for communications, and in the 1940s he forecast that man would reach the moon by the year 2000, an idea experts at first dismissed as rubbish.

When Neil Armstrong landed in 1969, the United States said Clarke "`provided the essential intellectual drive that led us to the moon.''    

Clarke wrote more than 80 books and 500 short stories and articles, and wanted to be remembered foremost as a writer.

Trained as a scientist, he was renowned for basing his work on scientific fact and theory rather than pure fiction and for keeping humanity at the heart of his technological visions.

In 1964, he started to work with the filmmaker Stanley Kubrick on the script for what became a groundbreaking movie that won audiences and accolades far wider than those of most previous sci-fi films -- "`2001: A Space Odyssey.''    

Based loosely on a short story Clarke had written in 1948, it dealt poetically with themes of human evolution, technology and consciousness and came to be regarded by many as one of the greatest films ever made.

The book version, a novel that Clarke wrote concurrently with the film, was published just after the film's 1968 release.

Clarke, one of the most prolific authors of his genre, was the last surviving member of a group of science-fiction writers known as the "Big Three.''  The two others were the Russian-born Isaac Asimov, who died in 1992, and Robert A Heinlein, a Missouri native who died in 1988.

"The thing about Clarke is he had this footprint lasting 60 years with a constant stream of publications,'' said Russell Galen, his New York-based literary agent for more than 30 years. "So he has a kind of stature from his long influence that puts him in a unique, elite group.''        

At a birthday celebration hosted by Sri Lankan President Mahinda Rajapaksa in December, Clarke said his mind continued to roam the universe as much as it did as a youth in the 1920s and 1930s, despite the fact he was wheelchair-bound.

"I would like to see some evidence of extraterrestrial life. I've always believed that we're not alone in the universe, but we're still waiting for E.T. to call us or give us some kind of sign,'' he said in a video message also posted on Web site www.youtube.com.

"Secondly, I would like to see us kick our current addiction to oil and adopt clean energy sources,'' he added. Finally, Clarke said he wished for an end to the civil war that has claimed some 70,000 lives in his adopted home of Sri Lanka since 1983.

Clarke first came to the Indian Ocean island in the 1950s for scuba diving and said he became a resident after he "fell in love with the place.'' In recent years, Clarke also had been working on the idea of a "space elevator.''    

"The golden age of space is only just beginning,'' Clarke forecast. "Over the next 50 years, thousands of people will travel to Earth orbit and then to the moon and beyond.

"Space travel and spac