Kirkland & Ellis has emerged as the top mergers and acquisitions (M&A) legal adviser in the oil and gas sector for the first three quarters of 2025 (Q1–Q3 2025) by value and volume, according to GlobalData, a data and analytics company. 

As per analysis of GlobalData’s financial deals database, Kirkland & Ellis advised on 36 transactions with a total value of $48.9bn. 

GlobalData lead analyst Aurojyoti Bose said: “Kirkland & Ellis was the top adviser by both volume and value during Q1–Q3 2024 as well. The US-based law firm not only led by both metrics but also remained significantly ahead of its peers during Q1–Q3 2025. 

“In fact, despite registering a year-on-year [YoY] fall in the total value of deals advised during Q1–Q3 2025, the firm outpaced its peers by a notable margin in terms of value. 

“During Q1–Q3 2025, the law firm advised on 13 billion-dollar deals that also included a megadeal valued at more than $10bn. The involvement in these big-ticket deals helped it maintain a significant lead by value over peers.” 

Simpson Thacher & Bartlett ranked second in deal value, advising on $35.6bn in transactions. It was followed closely by Sullivan & Cromwell at $35.5bn. Norton Rose Fulbright and Vinson & Elkins took the fourth and fifth spots, having advised on deals worth $32.8bn and $30.1bn, respectively. 

In terms of deal volume, Vinson & Elkins secured the second position with 22 deals, followed by Latham & Watkins with 14 deals, White & Case with 12 deals and Gibson, Dunn & Crutcher with ten deals. 

GlobalData’s league tables are based on the real-time tracking of thousands of company websites, advisory firm websites and other reliable sources available in the secondary domain. A dedicated team of analysts monitors all these sources to gather in-depth details for each deal, including adviser names.  

To ensure further robustness to the data, the company also seeks submissions of deals from leading advisers.