American International Group (AIG) and Canadian investment firm Onex Corporation have agreed to acquire specialty insurer Convex Group in a transaction valued at $7 billion, marking one of the largest insurance deals of 2025.
Deal Structure
Onex announced it will take a 63% controlling stake in Convex, while AIG will acquire 35%, with the remaining shares retained by Convex’s management team. The agreement values Convex at 1.9 times its tangible book value as of Q3 2025, reflecting the company’s rapid growth and strong underwriting performance.
As part of the broader strategic relationship, AIG will also purchase a 9.9% equity stake in Onex for approximately $600 million and commit $2 billion to Onex’s private equity and credit strategies over the next three years.
Convex’s Growth Trajectory
Founded in 2019 by industry veterans Stephen Catlin and Paul Brand, Convex has quickly established itself as a leading specialty property and casualty (re)insurer. The company is expected to generate up to $6 billion in gross premiums written in 2025, representing a 25% compound annual growth rate over the past three years. Convex has also delivered an average return on equity of 18% during that period, making it one of the fastest-growing players in the sector.
Strategic Rationale
For Onex, the acquisition consolidates its role as a long-term investor in Convex, having been a founding backer through its Onex Partners V fund. The deal strengthens its footprint in the global insurance ecosystem, where it has delivered consistent investment returns.
For AIG, the partnership provides access to a high-growth specialty insurer while deepening its ties with Onex. The additional equity stake and capital commitments are designed to align strategic interests and expand AIG’s exposure to private equity and credit markets.
Market Reaction
Onex shares surged by 8% on the Toronto Stock Exchange following the announcement, reflecting investor confidence in the transaction’s potential to drive long-term value. Analysts noted that the deal positions both Onex and AIG to benefit from Convex’s strong underwriting discipline and expanding global reach.
Outlook
The acquisition underscores the consolidation trend in the global insurance sector, as established players and private equity investors seek scale, diversification, and access to specialty lines. With Convex’s proven management team remaining in place, the new ownership structure is expected to provide stability while fueling further growth.
Conclusion
The $7 billion acquisition of Convex by AIG and Onex represents a transformational deal in the insurance industry, combining Onex’s investment expertise, AIG’s global reach, and Convex’s rapid growth trajectory. The partnership signals confidence in the resilience of specialty insurance markets and highlights the increasing role of private equity in reshaping the sector.
The AIG Towers, Los Angeles Picture by HanSangYoon
Sources: Onex Corporation press release; Convex Group statement; Yahoo Finance Yahoo Finance UK Yahoo Finance Onex Convex Insurance.
