British auction house Christie’s will put a Marilyn Monroe portrait by pop art pioneer Andy Warhol on sale in May. The work is expected to fetch a record value of $200 million.

The work, "Shot Sage Blue Marilyn," "is poised to be the most expensive painting of the 20th century ever sold at auction," said Alex Rotter, Christie's chairperson of 20th and 21st-century art.

The 1964 likeness of Monroe's face screen-printed with bright yellow hair, a pink face and light blue eyeshadow, is one of five paintings Warhol made of Monroe.

Warhol "used a screening technique on these paintings, on this painting, that he never used again. It was way too complicated, way too involved," said Rotter.

The work comes from the Thomas and Doris Ammann Foundation in Zurich. All the proceeds of the sale will benefit the foundation, which is dedicated to improving the lives of children around the world.

"The sale of this single painting will constitute the highest-grossing philanthropic auction since the collection of Peggy and David Rockefeller in 2018," said Christie's American Chairperson Marc Porter.

Christie's says the highest price paid for a Warhol was for the painting "Silver Car Crash (Double Disaster)," which sold for $105 million in 2013.