The deal takes BS's stake in Avesta, which makes stainless steel, to 49.9 per cent. The remainder of NCC's holding was placed, via BZW, with institutional investors in Sweden, the UK and elsewhere.
A BS spokesman said the company had the opportunity to take majority control, but was happy to hold Avesta as an investment rather than a subsidiary.
Avesta Sheffield was formed in November 1992 by the merger of Avesta AB with BS's stainless steel activities.
At that time BS agreed that if it bought more than 45 per cent of the venture it would make a general offer for all remaining shares. This agreement was terminated in August this year.
Last month the Sheffield company announed a return to profit for the first six months. BS shares fell 3.5p yesterday to 148.5p.