Ropes & Gray's newly-launched City practice has secured a trophy mandate after being instructed to advise cable group Liberty Global on deal finance for its €3.5bn (£3.1bn) takeover of Germany's Unitymedia.

The US law firm was instructed two weeks ago to handle the high yield debt backing the acquisition, one of the largest media deals since the credit crunch crippled the leveraged finance market in 2007.

Ropes & Gray's team is being led by one of its UK founding partners, Mike Goetz (pictured), and high yield specialist Jonathan Bloom, who joined the practice last month from White & Case. The firm is acting for UPC Germany, the vehicle set up to handle the acquisition.

The top 25 US law firm also drafted in a team to support the City office, which was launched in October by Goetz and Maurice Allen. The team includes US-based corporate partners Jay Kim, Craig Marcus and Jane Rogers. Liberty is an old client of Allen and Goetz.

The acquisition sees Liberty Global acquire Germany's second-largest cable company from private equity houses BC Partners and Apollo Management.

The deal was sealed late this week and sees BC and Apollo switch track after having been initially aiming to exit their investment via a public offering.

Freshfields Bruckhaus Deringer is acting as M&A counsel to Liberty in Germany with the firm's team being led by Hamburg-based corporate partner Michael Haidinger and technology, media and telecoms partner Thomas Tschentscher.

The firm worked alongside Liberty Global general counsel Ton Tuijten and the company's head of M&A Andrea Salvato.

Richard Trobman, the co-chair of Latham & Watkins' London corporate practice, is leading the team for the high-yield underwriters, Credit Suisse, Deutsche Bank, Goldman Sachs and JP Morgan.

Latham is also advising the vendors, fielding a team under corporate partners Hans-Juergen Luett in Frankfurt and Raymond Lin and Taurie Zeitzer in New York.

The use of high-yield financing on such a substantial deal will be seen as significant by M&A advisers at a time when a number of legal teams are predicting an upswing in bond-financed deals in Europe. Ropes & Gray and Allen & Overy have both recently recruited at partner level in London amid expectations of rising high-yield issuance.

Goetz told Legal Week that the mandate reflected Ropes & Gray's track record of acting as issuer counsel on high yield debt. The Boston-based practice, until last month one of the few major US law firms yet to have launched in London, is one of the US's leading private equity advisers.

The mandate will be viewed as a strategically important early win for the UK practice. Goetz and Allen signed on with Ropes & Gray after a much-publicised departure from Freshfields in August this year. The two finance specialists had joined the magic circle firm after quitting the City arm of White & Case in March 2008.

Commenting on Ropes & Gray's UK plans, Goetz said: "Our strategy is to be closely aligned to the private equity practice. It's a conservative firm but we've got a business plan that says we're aiming to be 60 lawyers in three years."

More US news, comment and analysis