Key Points:

Best selling fantasy author Robert Jordan has died of a rare blood disease aged 58, it has been reported.

Jordan - whose real name was James Oliver Rigney Jr - wrote the "Wheel of Time" series, which sold millions of books since the first - "The Eye of the World" - was published in 1990.

Associated Press (AP) news agency reported that Jordan died at the Medical University of South Carolina in Charleston on Sunday local time.

He was working on the 12th book of his "Wheel of Time" series at the time of his death.

The books follow Rand al'Thor on his journey to battle ultimate evil.

Jordan had spent most of his life in Charleston, telling AP in 2003: "What I write is certainly not set in South Carolina, but I have had a number of reviewers comment on the fact that I write with a distinctly Southern voice.

"It goes beyond more than simply where the story is set. I believe it is something we take in in the air and the water. It's a matter of word choices - of the rhythms of sentences and the rhythm of speech in particular."

Jordan had worked as a nuclear engineer before becoming a full time writer in 1977, AP said. He is survived by his wife, Harriet McDougal Rigney.