Fifty-five years ago, a member of the Sif union, which later merged into Unionen, bought Cavaliere by the Italian sculptor Marino Marini for only 10,000 kronor. The member was an art expert.

At first, the union did not realise how valuable the sculpture was. Hanna Brandt Gonzalez, deputy adminstrative director at Unionen, said that for several years, the prized work of art stood at the reception. It was later moved to the canteen.

Unionen was formed in 2008 after HTF and Sif merged. After the merger, the new union undertook an inventory of the works of art it possessed. Only then did it realise the true value of Cavaliere, so it decided to sell the sculpture.

“We cannot own such works, we cannot insure them,” said Brandt Gonzalez.

On Thursday, Cavaliere went under the hammer at Christie’s. The bronze sculpture was expected to go for 1.2 million to 1.8 million pounds (12.75 million to 19.12 million kronor, $1.92 million to $2.87 million).

However, interest in the union-owned sculpture proved to be intense before stopping at nearly 4.5 million pounds. Unionen will receive 3.95 million pounds, or nearly 44 million kronor of the purchase price, from the sale.

“We were a bit surprised that it was so much. There was talk of 20 million before,” said Brandt Gonzalez.