Coombe, chairman of the FTSE 100 finance directors group, will sit on the main board of a company that will have a combined market capitalisation of approximately £114bn. It will be one of Europe’s largest companies by market capitalisation.
The deal is expected to be completed by the summer. The two companies are thought to have resumed merger talks because a big obstacle to a smooth marriage will be removed when SmithKline chief executive Jan Leschly steps down in April.
Animosity between Leschly and Glaxo executive chairman Richard Sykes was seen as the main hurdle to an earlier pact.
The merger will create a group with combined sales from continuing businesses of approximately £15bn, and an estimated 7.3% share of the global pharmaceutical market.
The two partners, both of which are audited by PricewaterhouseCoopers, expect the deal to generate £1bn in annual pre-tax cost savings from the third anniversary of completion of which £250m is expected to be reinvested in R&D.