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What do A&O Shearman and Anya Taylor-Joy have in common?

Well, aside from their high-profile global reputations, both the firm and the actress represent a trend that's been taking the law firm industry by storm. They bridge the Atlantic, symbolising the merging of two different markets: the US and UK.

With the 2024 merger of Allen & Overy and Shearman & Sterling at the helm, these mergers purport to combine North American strength with British and European expertise. A forecast from consulting company Citi Hildebrandt on the legal market in 2026 also notes that one-in-five large firms consider an acquisition likely, with London positioned as the number two market for growth in law firm investment worldwide (and New York at number one).

In this article, I'll be breaking down this trend – as well as analysing its impacts on the legal industry at large.

For more on law firm mergers, check out this guide, featuring insights from Mayer Brown International LLP.

So, what's the deal? 

If you've been maintaining your commercial awareness, you may have noticed that the end of 2025 brought us a bunch of law firm mergers, many of which were transatlantic. Following hot on the heels of A&O Shearman in 2024, and Herbert Smith Freehills Kramer in 2025, three law firm mergers were announced late last year.

In November, UK-based Ashurst LLP announced a merger with Seattle-based Perkins Coie. The following month, Taylor Wessing announced its intention to merge with US firm Winston & Strawn London LLP. Less than a week later, Hogan Lovells – itself the result of a 2010 transatlantic merger between US firm Hogan & Hartson and British firm Lovells – announced its intention to merge with US firm Cadwalader, Wickersham & Taft.

Taylor Wessing and Winston & Strawn – which, once merged, will be known as Winston Taylor – has recently received the green light from partners, with completion to be expected sometime in May 2026.

Why the merge?

According to the Citi Hildebrandt report, many firms are turning to mergers to resolve the challenges currently facing the legal industry: reduced demand for legal services combined with increased expenses, the latter of which has only increased in the wake of AI adoption. Additionally, merging increases a firm's likelihood of attracting and retaining talent, alongside expanding into new markets.

What does this mean for…

The merged firms?

• Strengthening cross-border capability: the combined expertise of US firms with UK firms, many of which also have strong ties to Europe, strengthen the merged firm's overall offering and enable greater depth on complex multijurisdictional work.
• Complementing strengths: merging firms with different competencies creates a hybrid firm with a broader expertise. For instance, the proposed Winston Taylor merger will combine Taylor Wessing's strengths in intellectual property and technology with Winston & Strawn's US litigation and transactional offerings. For the firm's clients, this results in an expanded offering that doesn’t compromise on quality.
• Increasing scale and value: when firms merge, they bring together their strengths and priorities, which gives them more money and scale to invest in technology and competing for talent. The proposed merger between Ashurst and Perkins Coie, for instance, would create a $2.7 billion law firm situated in the top 20 largest law firms by revenue – whereas, on their own, each firm would place in the top 50. 
• Lost in translation: a disadvantage of merging firms, however, is the potential culture clash. US and UK firms can be vastly different in their structural organisation, models of financial compensation for partners and associates, and profit per partner. The challenges arising from this culture clash can even trigger lateral exits – causing the firm's leadership and talent to leave.

The mid-market?

• Partner mobility: this is a double-edged sword for smaller firms. A common consequence of law firm mergers is that the merged firms see lateral exits, creating a mobile partner market. While this may benefit mid-market firms that can hire experienced partners leaving the mega-firms, it can also result in uncertainty as they may lose talent to the larger, newly merged firms.
• Increased competition and pressure to specialise: firms that choose not to merge will need to refine their specialisms – either by sharpening their service offering or by focusing on UK-centric expertise – to compete more effectively with larger firms.
• Private equity: to compete with the scale and technological capabilities of transatlantic players, some firms may choose to accept external investment from private equity. While this can unlock additional resources, it also risks a loss of autonomy, meaning it may not be a firm’s preferred option.

The law firm market?

• Reshuffling of the legal industry: with the advent of transatlantic mergers, the market will become more segmented, with global megafirms at the top (in terms of value), followed by specialist and boutique mid-market firms.
• Changing business models: this trend showcases the increasing emphasis placed on scale, technology and international expansion. These new priorities may shape the structures and strategies of law firms in the near future.
• Accelerating adoption of legal tech and AI: with increased revenue, investment in legal tech and AI becomes more affordable for these megafirms. As a result, client expectations are likely to rise across the industry, with AI adoption emerging as a standalone trend shaping the sector alongside transatlantic mergers.

Although the mergers have yet to be finalised, the successive announcements alone signal a clear shift in the industry. With firms expanding their expertise across the Atlantic (and beyond), and the knock-on effects this will have on surrounding firms, the legal market will certainly be one to watch in the coming months.