Skadden Arps Slate Meagher & Flom, Allen & Overy (A&O) and Sidley Austin are among the firms to have taken roles on German pharmaceutical company Merck's $17bn (£10.5bn) acquisition of US laboratory supplies business Sigma-Aldrich.

Merck turned to Skadden as lead corporate advisers, which was announced last week. The firm is fielding a team that includes London-based M&A partner Hilary Foulkes, New York partners Peter Atkins and Neil Stronski and Frankfurt partner Katja Kaulamo.

The company also instructed A&O for advice on the bridge financing supporting the acquisition, which is set to conclude in the middle of next year, subject to shareholder and regulatory approval.

A&O's Frankfurt-based team was led by banking and finance partner Neil George Weiand, alongside counsels Mark Hallett and Alexander Schilling.

The two firms are working closely with Merck's group general counsel Friederike Rotsch and in-house counsel Norbert Kaliwe and Gabriel Medynska, all based in Germany.

The $15.6bn (£9.6bn) bridge financing needed for the all-cash transaction comprises a combination of bank loans and bonds, with JP Morgan and Societe Generale acting as underwriters.

Hengeler Mueller has been appointed to advise the banks on German law matters, with Frankfurt-based financing partners Thomas Cron and Nikolaus Vieten acting alongside tax counsel Mathias Link.

The firm is working with Cravath Swaine & Moore, with London-based partner Joel Herold advising on US law matters.

Meanwhile, Sidley Austin is acting for Missouri-headquartered Sigma-Aldrich.

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