Onex Partners Sells Convex to Onex Corporation and AIG for $7 Billion

A Strategic Win for Specialty Insurance: The $7 B Deal Shaping the Sector

When Onex Partners V—alongside other founding institutional equity partners in Convex Group Limited—agreed to sell Convex to Onex Corporation and American International Group (AIG) for $7 billion, it marked a significant milestone for the specialty property and casualty (P&C) insurance market. Under the deal, Onex takes approximately a 63 % stake and AIG about 35 %. The remaining interest stays with Convex's management team. (Reuters)

With a projected gross premium of up to $6 billion in 2025 and compound annual growth of about 25 % over the past three years, Convex has delivered an average return on equity of around 18 %. (markets.businessinsider.com)

This transaction offers multiple angles of interest to insurance-industry readers: the rise of specialty carriers, private-equity engagement in the P&C space, and the strategic positioning of legacy carriers and asset managers. Let’s dig in.

Growing a Specialty Platform: The Convex Story

Founded in 2019 by industry veterans Stephen Catlin and Paul Brand in partnership with Onex Partners V and co-investors, Convex launched as a de-novo specialty P&C carrier with no legacy liabilities. (Onex)

From its inception:

• Capital-raising: Convex closed with about $1.7 billion of committed capital in 2019. (PSP Investments)

• Follow-on funding: The company secured an additional $1 billion in equity in 2020, bringing commitments to more than $2.7 billion in just 18 months. (insurancebusinessmag.com)

• Business model: They built a low-cost operating platform, outsourced non-core functions, and focused on specialist underwriting talent across complex risk lines. (Onex)

In the deal announcement, Onex managing director Adam Cobourn said:

“Watching Stephen, Paul and the entire Convex team create this much operational scale and value from a standing start six years ago has been remarkable. We’re grateful for their partnership and for delivering such a terrific outcome for OP V and our partners.” (markets.businessinsider.com)

For the insurance industry this case highlights how a modern specialty insurer can be built from the ground up and reach significant scale in a relatively short period.

Why the Timing Matters

There are several strategic and market drivers behind this transaction that industry professionals will want to note:

• Hardening cycle and capacity constraints: Specialty insurers have benefited from rate momentum, underwriting discipline, and the ability to define complex risk niches. Convex’s early success captures that trend.

• Balance-sheet strength and independence: Starting legacy-free allowed Convex to focus purely on underwriting profitability rather than legacy claims drag. That’s a key differentiator for buyers.

• Private equity’s growing comfort with insurance platforms: Onex Partners has invested across the P&C value chain and particularly in founder-led businesses. The sale underscores the return possibilities and exit paths in the insurance space. (markets.businessinsider.com)

• Strategic realignment for incumbents and asset managers: For AIG, the deal offers access to a fast-growing specialty franchise and a complementary risk profile. For Onex, it reinforces their asset-management growth via insurance-linked and specialty platforms. (insurancebusinessmag.com)

Transaction Highlights in Brief

• Valuation: US $7 billion for the equity of Convex. (markets.businessinsider.com)

• Ownership structure: Onex ~63 %, AIG ~35 %, management retains remaining interest. (insurancebusinessmag.com)

• Closing timeline: Expected in the first half of 2026, subject to customary conditions. (markets.businessinsider.com)

• The deal also includes AIG acquiring a 9.9 % stake in Onex and committing ~$2 billion to Onex’s private equity/credit strategies over three years. (PE Hub)

Implications for the Insurance Industry

For insurers, reinsurers, brokers and capital providers, here are four key take-aways:

• Disruptor models have traction: Start-ups with strong underwriting leadership and a scalable operating model can attract significant capital and deliver high growth and profitability.

• Exit pathways are becoming clearer: Investors in insurance platforms are seeing meaningful exits, which bodes well for capital availability in the sector.

• Strategic partnerships matter: The alliance between a specialty carrier, a global insurance giant and a private-equity platform shows how multi-stakeholder deals are shaping the landscape.

• Scale remains critical: With Convex targeting ~$6 billion in gross premium for 2025 and delivering strong ROE, scale is increasingly a requirement for specialty players.

What to Watch Moving Forward

• Will other founders or private-equity-backed specialty carriers seek similar exits or partnerships?

• How will AIG integrate or otherwise work with Convex while preserving its underwriting culture and independence?

• Will Onex deploy further capital into additional insurance platforms, signaling a broadened strategy in the sector?

• How will insurers balance the drive for growth with maintaining discipline and underwriting performance, especially in complex risks?

Final Word

For industry players, the sale of Convex underscores that specialty insurance is neither niche nor marginal—it is firmly on the radar of large-scale investors and strategic buyers alike. As founder-led platforms prove their value and scale, the market for consolidation, capital deployment and strategic repositioning is intensifying. In such an environment, keeping a finger on both underwriting execution and structural flexibility will be critical.

“AIG’s investment reflects our confidence in Convex’s ability to consistently deliver outstanding results, strong returns, and sustained revenue growth.”
—Peter Zaffino, CEO of AIG (insurancebusinessmag.com)

The deal may close in 2026, but for those in the industry watching platform-scale specialty carriers, the momentum is now.