In May 1998, Zeneca announced that Tom McKillop , then the head of its drugs division, would succeed Sir David Barnes as chief executive, with Barnes becoming non-executive chairman of the company.  In November 1998, Zeneca announced that it was planning to sell its Zeneca Specialties division, including its biocides, industrial colours, lifescience molecules, performance and intermediate chemicals and resins activities.  Zeneca and Astra AB announced a £48 billion merger in December 1998.  In February 1999, it was reported that Zeneca would be suing the US Food and Drug Administration in respect of its decision to allow Gensia Sicor to produce a generic version of its anaesthetic Diprivan .  The merger between Zeneca and Astra AB was completed in April 1999, forming AstraZeneca plc .