The 21-year-old Olsen twins have never even lived in the 12 room Greenwich Village property - which they bought in 1994 for $7.3 million - but have now put it on the market for $12 million.

The millionaire stars have been renting out the spectacular condo for $35,000 a month.

Real estate agent Charlotte Van Doren said: "The apartment has been rented, and has been continually rented since they first bought it."

The apartment's main feature is a 53ft-long entertainment space with a glass-enclosed fireplace in the center.

Van Doren said: "It's very dramatic, very dramatic. You walk in and it's right there, bang."

The condo also boast views of the Hudson River from the living/dining room, the master bedroom, the master dressing room and the two other bedrooms.

It also has two separate 100sq ft walk-in closets.

Mary-Kate and Ashley - who in 2005 were estimated to have a combined net worth of $300 million - have a lucrative brand including their own fashion and accessories range, their own film series and successful acting and modeling careers.

Last week, Mary-Kate was admitted to hospital with a "kidney infection."

She has since recovered and has been spotted dining out and shopping with Ashley in New York.

The twins began their career at just six-months-old playing the part of baby Michelle Tanner on US TV show "Full House."