Biopharmaceutical concern Actelion started trading on Switzerland's leading blue chip stock index (SMI) on Monday, just eight years after its initial flotation.

Actelion replaced Basel-based speciality chemicals firm Clariant that dropped down to the medium sized stock index, the SMIM, after seeing the value of its shares fall in recent months.

Actelion's first drug, Tracleer, has recently been approved by the European Union as a therapy for pulmonary arterial tension.

"This inclusion is a milestone in our short history and an inspiration to continue the discovery, development and marketing of innovative medicines that have the potential to change patients' lives," Actelion managing director and chief executive Jean Paul Clozer said in a statement.

The company, based in Allschwil in canton Basel, was founded in 1997 and now has 1,700 employees and a presence in 25 countries.

The Swiss Market Index (SMI) is made up of the 20 largest and most liquid companies in Switzerland and represents some 85 per cent of the free-float capitalisation of all firms listed on the Swiss stock exchange.

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