2 Mark Rothko paintings owned by Rachel 'Bunny' Mellon star at NYC auction

Two boldface names — Rothko and Mellon — are getting prominent attention at an auction of post-war and contemporary art on Monday.

Two Mark Rothko paintings owned by Rachel "Bunny" Mellon for more than 40 years are among the offerings of Sotheby's evening sale.

Mellon, heir to the Listerine fortune, noted horticulturist and widow of philanthropist Paul Mellon, died in March at 103 at her Virginia estate.

"Untitled (Yellow, Orange, Yellow, Light Orange)," from 1955, could sell for $20 million to $30 million. "Untitled," created 15 years later, has a pre-sale estimate of $15 million to $20 million.

Other items from the Mellon collection including jewelry and furnishings will be offered in a series of sales Nov. 20-23. The total could realize more than $100 million.

Proceeds will benefit The Gerard B. Lambert Foundation, which supports The Oak Spring Garden Library in Upperville, Virginia. The library houses Mellon's collection of rare books, manuscripts and works of art related to landscape design, horticulture and natural history.

Mellon's grandfather Jordan W. Lambert created Listerine, and her father, Gerald Lambert, built a company that made everything from Dentyne to Schick razors. Paul Mellon had his own fortune, inherited from his Pittsburgh industrialist father and built on holdings in banking, coal, railroads, steel and aluminum.

Bunny Mellon was a self-taught botanist and close friend of Jacqueline Kennedy Onassis. In 1961, she redesigned the White House Rose Garden and later created another White House garden that was named for Kennedy after her death.

During their lifetimes, the Mellons donated hundreds of important artworks to museums, including the National Gallery of Art. The Washington, D.C., museum was founded in 1937 by Paul Mellon's father, Andrew Mellon.

On Tuesday, a third Rothko painting will go under the gavel at Sotheby's. "No. 21 (Red, Brown, Black and Orange)," purchased by art benefactors Pierre and Sao Schlumberger directly from Rothko's estate, could bring over $50 million.

The painting was first exhibited in the seminal exhibition "15 Americans" at the Museum of Modern Art in New York in 1952, a year after it was created. It has not been exhibited since a traveling retrospective of Rothko's work in 1971-72.

The current Rothko auction record is $86.8 million for "Orange, Red, Yellow."

Among other highlights at the Tuesday sale is Andy Warhol's 1974 "A group of Four Portraits of Sao Schlumberger," estimated between $2 million and $3 million.

Both Sotheby's and Christie's also are cashing in on the Jeff Koons mania sweeping the globe.

Sotheby's Tuesday sale features his "Moon (Yellow)" for an estimated $12 million to $18 million. It is one of five moon sculptures that Koons created in different colors, and the first of them to appear at auction. A pink version was displayed at the recent Koons retrospective at the Whitney Museum of American Art.

On Wednesday, Christie's is offering Koons' massive stainless-steel "Balloon Monkey (Orange)," with a pre-sale estimate of $20 million to $30 million.

Last year, Koons became the most expensive living artist when his "Balloon Dog (Orange)" was auctioned for $58.4 million.

The week of high-end sales concludes with yet another blockbuster offering from Christie's on Wednesday: two Andy Warhol portraits never before seen at auction — one of Elvis Presley and another of Marlon Brando. Each nearly 7 feet high, "Triple Elvis (Ferus Type)" and "Four Marlons" were acquired by German casino company WestSpiel in the 1970s. Potential bidders can expect to pay around $60 million for each.