Record-breaking May sales are expected at the major New York auction houses with a nude painting by Amedeo Modigliani estimated to bring $150 million, representing the highest auction estimate ever. The two week sale series at the major auction houses could possibly total over $2 billion.

A dozen artworks have estimates over $75 million, and highlights include a top-tier Picasso from the Rockefeller Collection at Christie's.

Modigliani's "Nu couche (sur le cote gauche)," or "Reclining nude," beats out the conservative pre-sale estimate of $100 million given to Leonardo da Vinci's "Salvator Mundi" last year. That Renaissance masterpiece fetched a record-busting $450 million at Christie's.

Sotheby's CEO Tad Smith told CNBC that he is confident with the Modigliani's high estimate considering the dwindling amount of "best of the best" artworks in private hands, saying, "The supply of great masterpieces isn't growing, it is actually shrinking."

The Modigliani, the artist's largest nude, was most recently on view in a Tate Modern exhibition, and was previously in the collection of casino mogul Steve Wynn who sold it in 2003 for $26.9 million to Irish billionaire John Magnier, according to Bloomberg.

The piece will star in Sotheby’s Impressionist and modern art sale on May 14.