The company said it would use the proceeds to cut its debt by about half, giving it more scope to expand its business in diagnostic products.
Nycomed, formed by the 1997 merger of Norway's Nycomed ASA and Amersham International, said last year it planned to sell its pharmaceuticals unit, Nycomed Pharma, which generated 19 per cent of its pounds 1.39bn sales in 1998.
Analysts said the price was low but the sale was needed. "There is slight disappointment about the price, but it gets them out of a non- core business so they can focus on core areas,'' said Ian Smith, an analyst with Lehman Brothers.
Nycomed shares rose by 2.5p to 504.5p yesterday.
Nordic Capital and Nycomed said they had formed a new company to acquire the drug unit, with Nycomed paying pounds 21m for a 30 per cent stake.
With a pounds 44m loan Nycomed will make to the new company, the transaction is worth pounds 340m.