Hollywood star Leonardo DiCaprio will appear Monday at an art auction at Christie's in New York where the actor hopes to raise millions of dollars for environmental protection.

Thirty-three works of art will go on the block, many by contemporary artists addressing environmental themes. Organizers of the "11th Hour Auction" estimate they could raise $15 million, Christie's said.

DiCaprio, currently starring in a huge new production of "The Great Gatsby," will attend the auction in Manhattan. In the catalogue for the auction, DiCaprio wrote that his foundation is "dedicated to protecting the last wild places on Earth and the critically endangered species that inhabit them."

"Our goal is simple: to support innovative conservation projects worldwide that protect nature, and improve the lives of local communities."

Among the works on sale will be "The Tiger," by Zeng Fanzhi, which comes from the collection of billionaire Francois Pinault. The pre-sale estimate was $1.5-2.5 million.

There are also works by the graffiti artist Banksy, a photograph by Richard Prince called "Silhouette Cowboy," and many works focusing on animals, such as Walton Ford's "Anthroponosis," which depicts the Bible's Eve walking with an orangutan.

A 2013 portrait of DiCaprio by Elizabeth Peyton is also on sale, estimated at $400,000-600,000.