US pharmaceuticals giant Johnson & Johnson on Thursday announced it was buying Europe's biggest bio-pharmaceutical firm, Switzerland's Actelion, for $30 billion (27.9 billion euros) in a deal that creates a new spin-off company.

The deal between the world's biggest producer of healthcare goods and Actelion, a leader in medicines treating high blood pressure, will create a new Swiss-listed firm called R&D NewCo focusing on the research and development of new drugs, the two companies said in a joint statement.

Johnson & Johnson will acquire all the outstanding shares of Actelion for $280 per share in a deal approved by the boards of both companies, with the tender offer to start by mid-February.

Actelion CEO Jean-Paul Clozel said the new R&D company would "allow us to continue with our successful culture of innovation", while Johnson & Johnson's CEO and chairman Alex Gorsky said in a statement that the acquisition of Actelion offered "compelling value" to shareholders in both companies.

"The addition of Actelion's specialty in-market medicines and late-stage products is consistent with Johnson & Johnson's efforts to grow in attractive and complementary therapeutic areas and serve patients with serious illnesses and significant unmet medical need," Gorsky said.

"In addition, the transaction structure will provide Johnson & Johnson flexibility to accelerate investment in its industry-leading, innovative pipeline to drive additional growth."

Actelion founder Clozel will found the new R&D company, which will initially be 16 percent owned by the US giant with the option of acquiring another 16 percent.

Johnson & Johnson has some 127,000 employees, operating the world's biggest medical device business as well as a huge pharmaceutical and consumer products wing that covers everything from baby products to band-aids.