Image caption Bacon painted Three Studies of Lucian Freud at London's Royal College of Art in 1969

A painting by Francis Bacon of his friend and fellow artist Lucian Freud has become the most expensive artwork ever sold at auction after it fetched $142m (£89m, 106m euros) in New York.

The triptych, Three Studies of Lucian Freud (1969), is considered one of Bacon's greatest masterpieces.

It was sold after six minutes of fierce bidding, Christie's auction house said.

The price eclipsed the $119.9m (£74m) paid for Edvard Munch's The Scream last year.

$100M ARTWORKS Edvard Munch, The Scream - $119.9m (2012)

Picasso, Nude, Green Leaves, and Bust - $106.5m (2010)

Alberto Giacometti, Walking Man I - $104.3m (2010)

Picasso, Boy With a Pipe - $104.1m (2004)

At the same auction, Jeff Koons broke the world record for a price paid for a single artwork by a living artist.

His sculpture Balloon Dog (Orange) - one of a series of five stainless steel sculptures in varying colours - fetched $58,4m (£36.7m).

The previous record for a living artist was set by a Gerhard Richter painting depicting an Italian city square, which sold in May for $37.1 million (£23.3m).

It was the first time Three Studies of Lucian Freud had been offered at auction and bidding opened at $80m (£50m, 60m euros). Its presale estimate was $85m (£53m, 64m euros).

Analysis In a world of supply and demand, it is not surprising that Bacon's huge triptych should sell for such an amount. It's unique, it's very high quality, and from an extremely famous period in the artist's life. The subject, and Bacon's remarkable use of colour, captures a moment in art history where his friendship with Freud was at its closest. It represents a relationship that has already moved into legend. What would be wonderful is if Freud's portrait of Bacon (painted around the same time but stolen from Berlin's National Gallery in 1988) was to be recovered and put back on public display, completing the story of these modern masters' mutual admiration.

A telephone bidder won with an offer of $127 million (£80m), which, after commission, means they will pay a total of $142m.

The auction house did not disclose the identity of the buyer.

Bacon, known for his triptychs, painted Three Studies of Lucian Freud in 1969 at London's Royal College of Art, after his studio was destroyed in a fire.

Francis Outred, head of Post-War and Contemporary Art at Christie's Europe, said the work was "a true masterpiece and one of the greatest paintings to come up for auction in a current generation".

"It marks Bacon and Freud's relationship, paying tribute to the creative and emotional kinship between the two artists," he added.

The pair met in 1945 and became close companions, painting each other on a number of occasions, before their relationship cooled during the 1970s.

Exhibited in Bacon's renowned retrospective at the Grand Palais, Paris in 1971-1972, the three panels that form the painting were separated in the mid-1970s.

One panel was shown at the Tate in 1985 before the three sections were reassembled.

The complete work was displayed in New Haven, Connecticut in 1999.

It got its first ever UK public viewing at Christie's in London in October this year.