British pharmaceutical giant GlaxoSmithKline on Monday announced a deal to pay as much as 3 billion Swiss francs (3.25 billion) to Swiss company Actelion to jointly develop and sell the company’s experimental sleeping pill.

Under the deal, Allschwil-based Actelion will receive an upfront payment of 150 million francs and 415 million francs upon registration of the drug, called almorexant. Also under the deal, Glaxo will receive exclusive worldwide rights, excluding Japan, to co-develop and commercialize almorexant.

Almorexant is part of a class of drugs known as orexin antagonists, designed to block receptors for brain chemicals that maintain wakefulness and regulate the sleep-wake cycle. The novelty with this drug is that patients taking it do not seem to experience a “hangover” effect the next day, which is common with many sleep pills already on the market.

“Almorexant has the potential to fundamentally change the treatment of sleep disorders. GSK is the ideal partner to work with Actelion to rapidly bring this novel medicine with the potential to restore normal physiological sleep – to insomnia patients all around the globe,” Actelion chief executive Jean-Paul Clozel said, according to AFP.

Two other unspecified uses may bring Glaxo as much as 2.74 billion francs in additional milestone payments, Glaxo said.

Both companies will share costs and profits resulting from their collaboration equally.

Besides Glaxo, other pharmaceutical companies that wanted to collaborate with Actelion included Novartis AG, Pfizer Inc, Schering Plough and Johnson & Johnson, bankers and analysts have said according to Reuters.

If almorexant, which will be involved in Phase III studies later this year, wins the regulatory approval, Actelion and analysts expect it to generate multibillion-dollar sales. Results of the drug’s safety and efficacy in insomnia patient are expected in 2009.

Actelion shares shot up 6.7 percent in Swiss trade.

Glaxo shares rose 0.8 percent in London, though that underperformed the broader market.