Celltech, the UK's largest biotechnology company, is to be bought by UCB, a Belgian pharmaceutical and chemical group, for £1.53bn (€2.25bn) as Europe's bankers gear up for a wave of consolidation in the healthcare sector.

Lazard is advising UCB on the recommended 550p a share offer - a 27.8% premium to Monday's closing price of 430.5p - and would be the second largest European pharmaceutical transaction announced this year. The sector has seen 20 deals worth €100m ($120m) or more, according to Dealogic, the investment banking research firm, and more are in the pipeline.