GLAXOSMITHKLINE HAS again extended its $2.6 billion offer to buy long-time partner Human Genome Sciences, until July 20th, in a hostile stand-off with the US biotech company.

The offer price remains unchanged at $13 per share. The decision to push back the closing date for the bid comes as no surprise since Human Genome effectively extended the war two weeks ago by setting a July 16th deadline for definitive takeover offers.

Buying Human Genome would give Britain’s biggest drugmaker the full rights to drugs on which the two companies collaborate. GSK said yesterday it remained willing to talk to Human Genome.

GSK has consistently refused to participate in the auction process being run by Human Genome’s advisers Goldman Sachs and Credit Suisse. Human Genome says it has had contacts with other companies, but bankers say GSK has a big advantage over rivals because of its partnerships around key drugs. The two companies together sell Benlysta, a drug for the autoimmune condition lupus, and they also collaborate on two drugs for diabetes and heart disease that could become significant sellers. – (Reuters)