BEIRUT, June 26 (Reuters) - A Lebanese calligrapher has completed a two-year project to hand write a copy of the Koran, Islam's holy book, in the rarely-used and delicate Arabic-language Diwani font.

Mahmoud Bayoun, 80, believes this is the first time this has been done. In Diwani font, each letter can be written six or seven ways.

"I wanted to do something no one has done", Bayoun told Reuters. "All fonts can be computerised but the Diwani font can't - because all computer fonts meet at a horizontal line but the Diwani (font) goes above, on and below the line."

The Koran, approximately containing around 6,300 verses, is traditionally written in the Naskhi font, which is designed to be easy to read and write.

Bayoun, who had previously written out the Koran four times in simpler script, has studied calligraphy since he was 14 and is the official calligrapher of Lebanon's prime minister.

He is unsure what will become of his latest work, but said that if the book does not find its own path, then it will be passed on to his children.

(Reporting by Basma Ayat, writing by Mark Hanrahan in London Editing by Jeremy Gaunt) ((Mark.Hanrahan@thomsonreuters.com;))