LONDON (Reuters) - A portrait of the late King of Pop, Michael Jackson, by the King of Pop Art, Andy Warhol, went on show in London on Thursday for three days in the lead-up to an auction in New York of the 1984 painting.

The portrait is on display at London's O2 Arena, the venue where Jackson was meant to hold his string of comeback concerts. He died on June 25 before the shows could happen.

The portrait was commissioned to celebrate the world record breaking sales of Jackson's "Thriller" album and was painted when both men were at the height of their careers.

It will go under the hammer in New York on August 18 at the Vered Gallery, starting with an opening bid of $800,000.

Janet Lehr, an art dealer and partner at the Vered Gallery, was refusing to disclose the owner of the painting.

"I can tell you that the owner is a true art collector, a lover of paintings, he bought the painting because he loved the painting," Lehr told Reuters Television.

"After Michael's death, I, an art dealer, went to the client and said this is the moment. There is no question that as with the death of some other very famous artists, performing artists, painters, their value catapulted in great excess of previous numbers."

The average auction figure reached in recent years for a work by Warhol, who died in 1987, in recent years is $17 million.

In the past the top price paid for a Warhol picture at auction was $71 million for a work called "Car Crash" and the top price for a Warhol portrait was $28 million for "Lemon Marilyn" of Marilyn Monroe. Both sold at Christie's in New York in 2007.

Lehr said it was impossible to guess what price the painting of Michael Jackson might expected to fetch but there were already a large number of interested bidders registered.

(Reporting by Reuters Television, editing by Belinda Goldsmith)