Ropes & Gray and Latham & Watkins have been appointed to advise on telecommunications group Altice's $6bn (£4bn) fundraising round to finance its acquisition of rival telecom company Oi's Portuguese assets.

Altice's offering to investors includes $5.2bn (£3.5bn) in high-yield bonds and $926m (£618m) in a seven-year term loan.

The acquisition was approved last week by shareholders of Oi subsidiary Portugal Telecom. In Portugal Altice already controls telecoms companies Cabovisao and Oni.

Ropes is advising Altice on financial aspects of the deal including bonds, revolving credit facilities and loan structures. London finance partners Michael Kazakevich and Jane Rogers are leading the firm's team on the transaction.

Latham is acting for the underwriters on the deal – a group of 14 banks led by JP Morgan Chase and Goldman Sachs. Latham London capital markets partner Scott Colwell and finance partner Dan Maze are working with New York finance partner Melissa Alwang on the deal.

Latham's reputation for capital markets and leveraged finance work in the City has grown in recent years after a string of high-profile lateral hires.

The firm has been building on its track record in the US where it has acted on more high-yield bond issues than any other firm over the last five years, according to Mergermarket's US M&A and buyout rankings.

This is the second-largest fundraising round launched by Altice owner and telecoms mogul Patrick Drahi in the last three months.

In November the Numericable founder arranged a €4.7bn (£3.68bn) rights issue for his French cable operator on which Cleary Gottlieb Steen & Hamilton and White & Case advised.