Marilyn Monroe wearing the iconic dress with its skirt billowing over a subway grate in the 1954 film The Seven Year Itch.

Perhaps the most famous costume in screen history, Marilyn Monroe's ‘subway’ dress from The Seven-Year Itchcomes to the auction block this June with an estimated value of $1-2 million.

The two-part sale, to be held in June and Dec. 2011, by California-based dealer Profiles in History, includes Monroe's halter-style dress with its memorably high-flying skirt. The dress may well surpass the $1.26 million paid 12 years ago for the film star's slinky sequined number worn when she sang 'Happy Birthday Mr. President."

Collected by actress Debbie Reynolds over the course of 50 years, the entire collection contains over 3,500 costumes, 20,000 original photographs, several thousand original movie posters, original costume sketches and hundreds of key props from film history.

Among the highlights are Judy Garland's original blue and white Dorothy "test" dress from 1939's The Wizard of Oz; Charlton Heston's signature tunic and robe worn in Ben-Hur of 1959; and the famous green-velvet “drapery” dress hat with bird adornment worn by Vivien Leigh as Scarlett O’ Hara in Gone with the Wind (1939).

Reynolds focused on Academy Award-winning films including My Fair Lady, The Sound of Music and Casablanca;the industry's top designers such as Travilla, Travis Banton and Edith Head; and pieces worn by film icons likeGrace Kelly, Marilyn Monroe, Judy Garland, Charlton Heston, Greta Garbo, Elizabeth Taylor, Bette Davis, Gene Kelly, Richard Burton and more.

“I heard the news that MGM was going to sell their inventory of costumes and props,” says Reynolds on how she started collecting, “I went everyday for weeks and focused on purchasing the costumes and props of Academy Award winning films. It soon turned into an obsession. Until now! I've concluded that my dream of having a museum cannot be fulfilled, so I have decided to share my fabulous collection with other collectors.”

The first 700 lots from "Debbie Reynolds - The Auction" will be offered by Profiles in History on June 18 at thePaley Center for the Media, 465 N. Beverly Drive, Beverly Hills, Calif. Previews will be held from noon to 5 p.m. on June 4-5, 8-12 and 15-17