A raft of UK, American and Swiss firms have secured advisory roles as Swiss pharmaceutical company Lonza Group agrees to buy US drug capsules maker Capsugel for $5.5bn (£4.4bn) from private equity company KKR.

The acquisition, which was announced today, will be financed with a combination of debt and equity financing.

Slaughter and May is advising  Lonza with a team led out of London by finance partners Robert Byk and Tom Vickers. The firm worked closely with the in-house legal and group treasury teams at Lonza, as well as Chicago's Jenner & Block who is advising on US law matters.

Bar & Karrer is advising Lonza on Swiss law.

Previously, Byk advised Lonza in 2011 on the financing of its acquisition of US-based Arch Chemicals.

Chicago's Jenner & Block is also providing counsel to Lonza on M&A matters with Bar & Karrer advising on Swiss law. The Jenner & Block team includes New York partners Kevin Collins and Martin Glass.

Simpson Thacher & Bartlett is acting for its longstanding client KKR on the sale with a team led by New York M&A partner Mark Pflug.

Linklaters is advising the banks involved on the debt aspects of the deal. Homburger is advising the banks on Swiss law for the equity aspects.

The Linklaters team consists of London banking partner Edward Aldred advising on debt aspects, and Frankfurt capital markets partner Marco Carbonare on the equity side.

In August, Slaughters won a mandate alongside Hogan Lovells advising pharmaceutical giant GlaxoSmithKline on its deal with Google parent company Alphabet to merge both companies' life sciences units.

Simpson Thacher and David Polk & Wardell last year landed the lead roles on UK pharmaceutical giant AstraZeneca's purchase of US company ZS Pharma for $2.7bn (£1.8bn). Simpson Thacher advised ZS Pharma.