So many works have come off Damien Hirst’s production line that more than 200 remain unsold by the artist’s main gallery in London.

The items include 34 butterfly paintings dating back to 2005; six medicine cabinets with price tags of up to £2.5m and a batch of 25 fly and resin coated skulls.

The “Hirst mountain” held by the White Cube gallery, and detailed in next month’s issue of The Art Newspaper, shows the challenges of selling mass-produced art.

Realising his British clientele can no longer soak up the quantity of art that he produces, Hirst is tapping the wider international market. He is putting 223 other works up for sale at Sotheby’s next month in his first sale of newly produced art at a major auction house.

White Cube has represented Hirst since the early 1990s. Artists usually prefer to sell new works through galleries which promote them with exhibitions. Hirst has opted for the auction house route partly because the commission is lower than the 40% often levied by galleries. He has also said that galleries can be “snobby” towards possible customers and “look down” on them.

At 43, Hirst is the most prolific major artist in Britain. He works with a large team of helpers at production facilities and studios in a system similar to that once operated by Andy Warhol in his “Factory”.

Hirst comes up with the ideas. While he creates some works himself, others are produced by his team, particularly those that come in consignments of identical or only slightly modified versions.

Of the 210 Hirst works still available through White Cube, nearly two-thirds were made in 2007, another 58 come from 2005 or 2006 and a few from earlier years. Many have been offered for sale at exhibitions.

They include several works valued at more than £1m, such as the butterfly paintings and medicine cabinets. Another is his Periodic Table of the Elements, a £3m work. There are several pieces called Fact depicting his wife Maia and the birth of their son Cyrus. These are valued at up to £2m.

Familiar-looking works that remain unsold include Love’s Paradox 2007, two cows pickled in formaldehyde and suspended in tanks, priced at £4.5m. Also in stock is a version of Charity, a 22ft high £2.5m statue based on the models of a little girl with a teddy bear and a collection box which were seen on Britain’s streets during the 1960s and 1970s in fundraising for Scope, then the Spastics Society.

Nearly all the items have been displayed at shows such as Beyond Belief, held last summer. The exhibits there included a £50m jewelled skull, now owned by a consortium that includes Hirst and Jay Jopling, proprietor of White Cube.

Other “for sale” Hirsts include three editions of The First Relic, a platinum sculpture in the shape of a jawbone, and an edition of the Virgin Mother, the 35-ft high bronze statue showing the insides of a pregnant woman.

Tim Marlow, exhibitions director at White Cube, did not confirm or deny the existence of the unsold Hirsts, but said: “I’d be very happy if there were 200 Hirsts still available because he is the most successful artist in the world.”

Hirst’s Sotheby’s sale will be watched carefully by other artists. The two-day auction is expected to realise at least £65m. The most expensive work is The Golden Calf, a work of gold, gold-plated steel and glass in formaldehyde solution on a marble plinth. Its estimated price is between £8m-£12m.

Other highly priced works include The Kingdom, a new shark in a tank, estimated at up to £6m. Most buyers are expected from newer markets such as India, Russia and the Gulf.

On Thursday there will be two “highlight” previews at The Bridge, a private golf club in the Hamptons in New York state and at the Oberoi hotel in Delhi. This will be Hirst’s first show in India. “Until now Indian collectors have primarily shown interest in art from their own culture,” said Oliver Barker, senior international specialist at Sotheby’s. “Now they are thinking global.”

Meanwhile, Hirst is calling a halt to some of his best known ranges. On Sotheby’s online service he says that he wants to stop creating butterfly and spot works and plans few more formaldehyde works.

He also explains why he has gone to Sotheby’s. “It takes a bit of courage or madness to get to where you just cut out the galleries and take a whole load of box-fresh pieces straight to market,” he said. “No strings. Highest bidder wins.”

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