Slaughter and May, Cravath Swaine & Moore and Wachtell Lipton Rosen & Katz are among a line-up of firms advising as Johnson & Johnson agrees to buy Actelion for $30bn (£24bn).

The US healthcare giant has agreed to buy the Swiss biotech company in an all-cash deal, which includes spinning off Actelion's research and development unit.

Swiss firm Niederer Kraft & Frey is taking the lead role for Actelion, alongside Slaughters and elite US firm Wachtell.

The trio's integrated legal team is being led by Niederer partners Philipp Haas and Ulysses von Salis, alongside Slaughters City corporate partners Simon Nicholls and David Johnson, and Wachtell corporate partners Dan Neff and Greg Ostling.

Johnson & Johnson has instructed Cravath, Swiss firm Homburger and Boston life sciences boutique Sexton Riley.

Cravath's team is being led by North America M&A head Robert Townsend and corporate partner Damien Zoubek.

Johnson & Johnson recently signed a five-year contract with alternative legal services provider Axiom, which will provide the pharma giant with multi-shore contract management services and support the company's global procurement contracting function.

Slaughters is also currently advising Swiss pharma company Lonza Group on its proposed acquisition of US drug capsules maker Capsugel for $5.5bn (£4.4bn) from private equity company KKR. Simpson Thacher & Bartlett is acting for longstanding client KKR, while Linklaters is advising the banks.