A portfolio of 10 screen prints by Andy Warhol, featuring images of Marilyn Monroe, has sold for $1.8m at Phillips in New York.
The auction took place on March 6.
Warhol was obsessed by Monroe and in particular her ability to control and project her public image. He created his first screen print of the star in 1962, the year she died, using a publicity image from the film Niagra (1953).
The prints featured in the portfolio were produced in an edition of 250 in 1967, and are prime examples of Warhol's skill in manipulating mass produced images.
In 2013, one of the earliest of Warhol's silkscreen prints of Monroe from 1962 sold for $38.2m at Phillips New York.
An untitled painting by contemporary artist Rudolf Stingel dating to 1997 made $989,000, an increase of 41.2% on a $700,000 estimate.
It features flecks of bright orange over a matte black background and is typical of the work the artist produced during the 1990s. It makes use of gauze to create a uniquely tactile surface.
Stingel's auction record was set at $1.2m for a self-portrait at Phillips New York last year, suggesting that his work may have increased in value.
Ceramicist Ken Price's Pink Egg (1964) also performed well, achieving $509,000 against a $400,000 estimate - an increase of 27.2%.
Last year a unit from his seminal Happy's Curios exhibition (1972-1978) made $293,000 at Phillips.