Norton Rose Fulbright and Kirkland & Ellis were the top mergers and acquisitions (M&A) legal advisers in the oil & gas sector during the first half (H1) of 2025 by value and volume, respectively, according to the latest legal advisers league table by GlobalData, which ranks legal advisers by the value and volume of M&A deals on which they advised.

Based on its Deals Database, the leading data and analytics company has revealed that Norton Rose Fulbright achieved its leading position in terms of value by advising on $27.1 billion worth of deals. Meanwhile, Kirkland & Ellis led in terms of volume by advising on a total of 18 deals.

Aurojyoti Bose, Lead Analyst at GlobalData, comments: “Kirkland & Ellis was the top adviser by volume in H1 2024 and retained the leadership position by this metric in H1 2025 as well. Apart from leading by volume in H1 2025, Kirkland & Ellis also held the second position by value.

“Meanwhile, Norton Rose Fulbright registered a massive jump in the total value of deals advised by it during H1 2025 compared to H1 2024 due to involvement in big-ticket deals. Resultantly, its ranking by value took a significant leap from 64th position in H1 2024 to the top position in H1 2025. Four of the five deals advised by Norton Rose Fulbright during H1 2025 were billion-dollar deals*, which also included a mega deal valued more than $10 billion.”

An analysis of GlobalData's Deals Database reveals that Kirkland & Ellis occupied the second position in terms of value, by advising on $24.1 billion worth of deals, followed by Vinson & Elkins with $23.3 billion, Simpson Thacher & Bartlett with $21.3 billion, and Blake Cassels & Graydon with $16.7 billion.

Meanwhile, Vinson & Elkins occupied the second position in terms of volume with 14 deals, followed by Gibson, Dunn & Crutcher with eight deals, Akin Gump Strauss Hauer & Feld with seven deals, and Simpson Thacher & Bartlett with six deals.
Source: Global Data