Maria Sharapova has pulled out of the $1.5 million (760,000 pound) Dubai Championships citing a viral illness.

The Australian Open champion, who also won in Qatar last week, is unbeaten in 2008 and had been scheduled to play her first match in Dubai on centre court in Tuesday's evening session.

"Unfortunately I have been battling a virus for several days and it's reached a point where I'm unable to compete," Sharapova said in a statement.

"I flew to Dubai right after my final in Doha and woke up on Monday feeling really fatigued and stuffed up with a cough.

"After trying to hit a little bit in the evening, I came to the conclusion that I'm realistically not going to be ready to play five matches in five days.

"It's been such a great and healthy start to the year, and I don't want to jeopardise that by making the wrong decisions, as I have in the past.

"This is really disappointing to me, but I do intend to come back to Dubai next year and hopefully have a great tournament."

Belgium's Justine Henin heads a strong field at this year's event, where she is joined by Svetlana Kuznetsova, Ana Ivanovic and Jelena Jankovic.

World number one Henin is the reigning champion and has won the Dubai title four times in total.