Two paintings by Signac and one by Pissarro are expected to fetch as much as £20m

Unseen for 25 years, they all come from a very private American collector

Supported by transformational new technology, the sector is ditching its traditional business model in favour of the luxury goods market

Pastoral landscape sold at Sotheby’s was once owned by Royal Holloway college

We look back at the biggest art sales of the year, which reveal a concentration on New York over London and a continued dominance of 20th century male artists

Sotheby’s sale is set to raise half a million pounds, offsetting money lost in Inigo Philbrick deals

While her role grows to cover departments such as Old Masters, second global division will include luxury objects and decorative art, jewellery and wine

A London-based investment company must repay more than $5.3m to the auction house, which refunded an American client for work

We look back at the stories that have overturned the art world order this year

December auction generates less than half the total of last year's sale, with several lots failing to sell

From a miracle scene seized by Nazis to a pensive painting by Joseph Wright of Derby, our pick of highlights from this week's auctions and fairs

The artist William Powell Frith 'almost collapsed' at the honour of being commissioned by the famous writer to paint his heroine Kate Nickleby

Painting depicting the Holy Family in an evening landscape has been owned by a Manhattan family for more than 60 years

Will new management be able to grow the newly privatised auction house on a tight budget?

Executive salaries rises, while junior staff struggle to move up the ladder

Small works won out at Sotheby's and Christie's as top lots went for their low estimates or were withdrawn

Overall sales were down by around 30% but beyond the disappointing headline figures, women and minority artists shone

Sculpture—estimated at £1m—was removed from the street by Andy Link in 2004 but later “liberated” from his East End garden

Andy Link says sculpture for which he demanded £5,000 in ransom was later stolen from him. Banksy’s former dealer says otherwise

Record prices were set for Charles White, Brice Marden, and Wayne Thiebaud, while a Clyfford Still painting prompted a prolonged bidding war

Work acquired by Van Gogh Museum in Amsterdam and the Drents Museum in Assen is one of few to survive from the artist's visit to Drenthe

The newly private auction house led the night's lots with its known money-maker Claude Monet, and set a world record for the Polish artist Tamara de Lempicka

Can the quality of the smaller works coming up during "gigaweek" quell economic jitters?

If not immune to geopolitical unrest, then perhaps art is a refuge for money that is struggling to find its way into other assets

The $250,000 prize money will be shared between several São Paulo organisations

One of the works was looted by the Nazis from Jewish collector Jacques Goudstikker, but is now being sold by his heir after restitution

Smith leaves after four and a half years with a $28.2m severance deal, including $16.9m in shares, and will remain as a senior adviser to Stewart

Jose Mugrabi and Antoine Arnault among collectors bidding at "white glove" sale of works by François-Xavier and Claude Lalanne

Our pick of highlights from the next fortnight's auctions and fairs