Swedish petrol company, existed 1953 - 1964.
In 1953, the mining company Stora Kopparbergs and Transatlantic (a shipping company) entered the petrol business by forming the company Koppartrans. It was acquired by Shell in 1964, but its logo was still visible on petrol stations as much as a decade later.
The logo (a dragon in the shape of a K) and the company's graphical profile have been the subject of some nostalgia, and there are a number of fansites like the below:
Recently, a denimwear manufacturer seems to have picked up the name along with the logo, see
(Beware of Flash graphics).