PE-Backed Grant Thornton US Eyes M Australia Acquisition — Wall Street Goes Global

Subtitle: New Mountain Capital's 60% stake in Grant Thornton US is already driving cross-border M&A. Australia could be the first of many.

Private equity is no longer content buying US accounting firms. Now it's going global.

Grant Thornton US - majority-owned by New York's $60 billion New Mountain Capital since May 2024 - is in active due diligence to acquire Grant Thornton Australia, the country's 8th-largest accounting firm with $270 million in annual revenue.

If the deal closes, it'll mark one of the first major cross-border acquisitions driven by PE money - a US firm swallowing a foreign network member to consolidate globally.

The Backstory

Grant Thornton US closed a "significant investment" with New Mountain Capital in May 2024. The Wall Street Journal reported New Mountain's group took a 60% stake, making it the majority owner of the 7th-largest US accounting firm.

At the time, GT US said the deal would "accelerate business strategy" and "add scale and resources." Translation: PE money means aggressive growth, and that growth isn't stopping at US borders.

Fast forward less than a year, and GT US is reportedly in advanced negotiations to buy GT Australia outright. The Australian Financial Review broke the story March 8, 2026, citing sources close to the deal.

What Makes This a Big Deal

Grant Thornton isn't a single firm - it's a global network of independent member firms operating under a shared brand. Each country's GT firm is technically separate, with its own partners, ownership structure, and P&L.

But PE changes that math. When New Mountain took majority control of GT US, it gave Wall Street a foothold inside the network. Now that PE-backed US firm can buy other network members, consolidating ownership across borders.

This is the first time we've seen a PE-fueled US firm actively pursue a foreign network member at this scale. If it closes, it sets a precedent for how PE consolidates globally - not just firm-by-firm within the US, but country-by-country across the network.

Why Australia?

GT Australia posted $270 million in revenue last year. It's the 8th-largest firm in the country, with strong audit, tax, and advisory practices. For New Mountain, it's a regional expansion play - Australia is a high-margin, English-speaking market with deep ties to US business interests.

It's also a relatively easy acquisition. GT US and GT Australia already share a brand, client referral systems, and audit methodology. The integration risk is lower than buying a competitor firm with different systems and culture.

And with GT US now backed by $60 billion in PE firepower, the deal likely pencils out: Buy GT Australia, consolidate back-office functions, cross-sell services to US clients with Australian operations, and drive margin expansion.

The Bigger Trend

This isn't happening in a vacuum. PE has been flooding the US accounting industry for years - Grant Thornton, Citrin Cooperman, Aprio, Kaufman Rossin, and dozens of others have taken PE investments or sold to PE-backed platforms.

But the US market is getting crowded. Multiples are high. Competition for deals is fierce. So PE is looking outward - to Canada, Australia, the UK, and Europe - for the next wave of consolidation.

The Grant Thornton network is especially ripe for this. With 73,000 employees across 150+ countries, it's the world's 7th-largest accounting network by revenue. If New Mountain can consolidate multiple country members under GT US ownership, it creates a PE-controlled global firm that competes directly with the Big 4.

That's the end game: Not just a bigger US firm, but a PE-backed global accounting powerhouse.

What It Means for CPAs

1. Independence gets complicated.
When a US firm and a foreign firm merge under single ownership, audit independence rules get trickier. If GT US owns GT Australia, they're no longer separate firms for conflict-of-interest purposes. CPAs working on multinational clients will need to rethink engagement acceptance and rotation policies.

2. Network relationships are changing.
For decades, global accounting networks operated as loose federations - independent firms sharing a brand and referral pipeline. PE is collapsing that model. Expect more network members to be acquired by PE-backed US firms in the next 3-5 years.

3. Career paths are shifting.
If you're a partner at a network member firm, your equity could be on the table sooner than you think. PE doesn't buy firms to let them run independently - they buy to consolidate, rationalize, and extract value. That means partner comp structures, retirement plans, and governance will change.

4. The Big 4 are watching.
Deloitte, PwC, EY, and KPMG can't take PE investment due to audit independence rules. But if PE-backed firms like Grant Thornton start consolidating globally, they'll have the capital and scale to compete for Big 4 clients. That's a structural shift the profession hasn't seen in decades.

The Bottom Line

Grant Thornton US buying Grant Thornton Australia isn't just a regional M&A deal - it's Wall Street taking the accounting profession global. If this closes, expect more PE-backed US firms to start shopping for foreign network members.

The playbook is clear: PE money buys a majority stake in a US firm, that firm uses PE capital to acquire foreign partners, and Wall Street ends up owning a global accounting platform.

CPAs who think PE consolidation is a US-only phenomenon are about to learn otherwise.