Freshfields Bruckhaus Deringer and Allen & Overy (A&O) have scooped lead roles on the latest major merger deal in the European energy sector as Dutch utilities giants Essent and Nuon tie the knot in a €24bn (£16bn) deal.

Freshfields is advising longstanding client Essent on the merger – the largest-ever M&A deal in the Netherlands – with Amsterdam-based corporate partner Steven Perrick and competition partner Winfred Knibbeler heading the team.

A&O is advising Nuon, with Dutch M&A partner Jan Louis Burggraaf – who has advised the company for a number of years – spearheading the deal team alongside competition partner Paul Glazener.

The deal continues a wave of major M&A deals in the energy sector over the last 18 months. In September 2005 magic circle rival Clifford Chance (CC) scooped a lead role advising Endesa on an ongoing bidding war that has seen offers of up to €22.5bn (£14.8bn) made for the Spanish utilities giant.

Private equity-backed deals have further boosted deal activity in the Benelux region, with a heavyweight consortium of private equity firms led by Kohlberg Kravis Roberts & Co offering €7.3bn (£5bn) for Dutch media giant VNU.

That deal handed a role to local independent firm De Brauw Blackstone & Westbroek, which teamed up with New York powerhouse Simpson Thacher & Bartlett to advise VNU, while CC acted for the buyout consortium.

Commenting on the Essent-Nuon tie-up, A&O's Burggraaf said: "It is a massive deal in a market of this size and should keep us busy for a number of months yet."