Rokstone has reorganized its senior leadership team around the deployment of its ATOMX platform, integrating underwriting, risk oversight, and operations across its global business.
The international specialty re/insurance managing general agent, part of Aventum Group, confirmed three senior appointments: Nadine Kearney (pictured left) will join the board as chief underwriting & risk officer, subject to regulatory approval; Robin Ungless has been named chief underwriting officer, specialty; and Martin Thomas (pictured right) has been promoted to global chief operating officer.
All three roles are linked to the rollout and use of Rokstone’s proprietary underwriting platform, ATOMX, across underwriting, portfolio management, and operational processes.
ATOMX is designed to eliminate inefficiencies, reduce errors, and accelerate underwriting processes, enabling faster and more precise outcomes.
Kearney will oversee global underwriting and risk strategy, including the application of ATOMX within a governed framework. Her remit includes underwriting standards, portfolio management, enterprise risk management, and the use of capacity arrangements.
Ungless will oversee underwriting performance across specialty lines. His responsibilities include underwriting discipline, program management, and the use of ATOMX to support data-led risk assessment.
Thomas will oversee operational delivery and governance structures, with responsibility for embedding ATOMX across teams, aligning underwriting operations with governance requirements, and supporting business scalability.
Kearney joined Rokstone in 2022 as head of portfolio underwriting and later served as chief underwriting officer – specialty. She has 16 years of experience across portfolio management, underwriting, governance, risk management, and compliance.
Her appointment introduces a board-level role overseeing underwriting and risk across the business, including the implementation of an enterprise risk management framework.
Ungless joined Rokstone in February 2020 as a portfolio manager and has nearly six years with the firm. He brings 35 years of experience across specialty and reinsurance markets.
In his current role, he is responsible for underwriting performance across specialty lines, including underwriting discipline and program management supported by ATOMX.
Thomas joined Rokstone in June 2024 as head of underwriting management. His background includes underwriting management, operational control and governance frameworks, risk monitoring, regulatory governance, audit processes, underwriting authorities, licensing, and business change management.
As global chief operating officer, he will oversee operational execution and governance while supporting the implementation of ATOMX across the organization.
“I’m delighted to announce these well-deserved promotions across three critical roles which together strengthen our governance and control environment whilst preserving our agility and entrepreneurial culture,” said Ian Anson, global CEO at Rokstone. “As we continue to grow and evolve at pace, the importance of strong underwriting and operational leadership is pivotal to our success. Nadine, Robin and Martin have exceptional technical, operational and leadership skills, all of which will be invaluable as we continue to strengthen and diversify our underwriting capabilities.
“Together they will set and execute an underwriting strategy that will redefine global specialty underwriting. Enhancing our readiness to execute and optimise broad portfolio partnerships and crucially demonstrate to our partners that we prioritise a culture of underwriting excellence and governance.”
The leadership changes follow a series of underwriting unit launches and portfolio additions during 2025.
In May 2025, Rokstone introduced an international casualty division, adding to four other casualty-focused units launched within months, including US excess casualty, UK and Ireland casualty, sports and leisure event casualty, and US commercial risks. The five units are projected to generate more than $850 million in gross written premium within five years, according to company statements reported at the time.
The casualty expansion is supported by A-rated Lloyd’s capacity, enabling global underwriting across multiple lines.
In July 2025, the firm also launched a surety division, targeting the bond market and complementing its existing credit and surety treaty business, according to industry reports. The unit was introduced alongside a $10 million Lloyd’s-backed facility for directors and officers and professional indemnity coverage for financial institutions across the UK, Europe, and the Caribbean.
Rokstone has also expanded its facultative property and energy underwriting through a binder agreement with Lloyd’s Somers Syndicates, taking its direct and facultative portfolio beyond $300 million in gross written premium.
