BRITISH biotechnology specialist Amersham International yesterday announced plans to merge with rival Norwegian firm Nycomed to create a global group worth Pounds 1.8 billion sterling. The move gives the new company, Nycomed Amersham, market leader positions in both the in-vivo diagnostic imaging and research-based biotech supply sectors. Based on their current trading performances, Nycomed Amersham anticipates pro-forma revenues of Pounds 1.5 billion sterling and profits around the Pounds 244 million mark.