Private equity firm Warburg Pincus is backing the launch of Unity Advisory, a UK-based boutique accounting and consulting firm founded by former EY and PwC senior leaders, in a move poised to shake up the professional services sector.

The firm, chaired by former EY UK boss Steve Varley and led by CEO Marissa Thomas—previously COO at PwC UK—is set to launch by June with up to $300m in backing from Warburg Pincus. Unity will offer tax, accounting, technology consulting, and M&A advisory services, but will deliberately exclude audit to avoid the regulatory complexities and conflicts of interest that often entangle Big Four firms.

“The Big Four are a classy bunch of service providers, but CFOs are increasingly seeking a proposition that is client-centric, AI-led, and free from audit-related conflicts,” said Varley.

Thomas, who spent 31 years at PwC and led its UK M&A and tax practices, said Unity aims to attract professionals with Big Four experience and target mid-sized corporates—particularly those backed by private equity—with revenues between £500m and £1.5bn. She added that Unity’s lower central cost structure would allow for more flexible fee models, including performance-based and value-sharing arrangements.

Warburg Pincus managing director David Reis described Unity as “a new kind of platform that challenges the status quo in how CFOs and finance teams are serviced.”

The launch of Unity follows a wave of private equity interest in the global accounting sector. In the UK, Cinven acquired a majority stake in Grant Thornton last year, while Warburg Pincus has previously backed ventures such as Steve McGill’s specialty insurance platform.

Unity Advisory reflects a broader shift toward private capital reshaping traditionally partnership-led industries through strategic investment, operational focus, and long-term value creation.

Source: Financial Times