The deal would give T&N an important presence in the German automotive market, where analysts had complained it was weak, but the acquisition needs approval from regulators.
T&N has struck a complex deal in which Commerzbank and institutional investors bought Metallgesellschaft's interest in Kolbenschmidt. If the German authorities approve the purchase T&N has options until 31 March to buy 52.5 per cent of the company.
Metallgesellschaft had reached an agreement with Dana, a US group, but this fell through about four weeks ago.
Colin Hope, T&N's chairman and chief executive, said there was no time to get regulatory approval but Metallgesellschaft had to meet a deadline.
Kolbenschmidt makes diesel and petrol pistons and oil and water pumps for the automotive industry, supplying customers worldwide. The company has manufacturing sites in Germany, Brazil, France, Italy and the US. In the six months to 31 March it made a loss of DM12.7m ( pounds 5.3m).
Mr Hope said the two companies' products faced limited overlap but there was considerable potential for cost-cutting. The shares fell 5p to 220p.Reuse content