GlaxoSmithKline on Wednesday moved to become the pharmaceuticals company with the broadest range of products to tackle the swine flu pandemic, as it unveiled plans for the sale of masks and diagnostics to add to its fast-growing vaccines and antiviral medicines business.

The UK company signalled a strong upsurge in demand from governments for its vaccines and its antiviral drug Relenza as the infection spreads, with plans to sharply expand manufacturing capacity.