White & Case and Slaughter and May have advised on the $8.8bn (£5.5bn) merger of subsea engineering and construction companies Acergy and Subsea 7.

White & Case acted for Acergy with a team led by City M&A partner Peter Finlay and New York M&A partner Gregory Pryor alongside Brussels competition partner Mark Powell and City partners Peita Menon (tax), Nicholas Greenacre and Stephen Ravenscroft (employment) and Gavin McLean (finance).

Meanwhile, Slaughters advised Subsea 7 with a team including corporate and commercial partner Tim Boxell and finance partner Stephen Powell.

Acergy was also advised on Norwegian, Cayman and Luxembourg law by Wikborg Rein, Walkers and Elvinger Hoss & Prussen respectively, while Subsea 7 took advice from Wiersholm, Maples & Calder and Arendt & Medernach.

White & Case's Finlay said: "The oil and gas sector has witnessed healthy levels of M&A activity, which we expect to continue. It has been interesting to see in parallel ongoing M&A activity in the energy services sector.

"What was particularly interesting about this deal was the project management required to pull together the relevant transactional considerations in a number of jurisdictions, including Luxembourg, Norway, Cayman Islands, the US and the UK."

The combined entity, known as Subsea 7, will provide services in seabed-to-surface engineering and construction, procurement and installation.

The news follows a number of recent hires for White & Case's City arm, including Simmons & Simmons corporate partner Gavin Weir, bank finance partners Jacqueline Evans and Lee Cullinane from Mayer Brown and former Freshfields M&A partner David Crook, all of which were announced within the last month.