Brian Duperreault

Brian Duperreault
Born	(1947-05-08) May 8, 1947 Paget, Bermuda
Occupation	Insurance executive
Known for	CEO of American International Group, ACE Limited, Marsh & McLennan Companies, Hamilton Insurance Group

Brian Charles Duperreault (born May 8, 1947) is an American insurance leader originally from Bermuda who stepped down as executive chairman of American International Group in December 2021.

Duperreault launched his insurance profession in 1973 as an actuary at AIG, eventually overseeing all of AIG's international divisions. Regarded as a likely candidate to succeed CEO Hank Greenberg, he departed AIG in 1994 to become the head of ACE Limited, a specialty insurer based in Bermuda. Serving as chairman and CEO for ten years, he transformed ACE into a global multi-line insurance and reinsurance entity, significantly contributing to Bermuda’s prominence as a key insurance center.

Following his retirement in 2006, Duperreault returned in 2008 to lead Marsh & McLennan Companies through recovery after a damaging bid-rigging scandal. As president and CEO over five years, he restored profitability, rebuilt corporate reputation and employee morale, and regained trust from investors and clients.

After retiring again in 2012, he co-founded Hamilton Insurance Group in Bermuda in 2013 alongside hedge fund Two Sigma Investments, with an emphasis on sophisticated data science and predictive analytics. Under his guidance, Hamilton grew through acquisitions within insurance and reinsurance sectors, including expanding U.S. operations and establishing a Lloyd’s syndicate. In 2016, Hamilton collaborated with AIG and Two Sigma to introduce Attune, an algorithm-driven platform offering commercial insurance online to small- and medium-sized enterprises.

In May 2017, amid ongoing post-2008 financial crisis challenges, Duperreault was appointed CEO of AIG following Peter Hancock’s resignation. He suspended share repurchases to focus on strategic acquisitions, overhauled senior leadership and underwriting departments, and reorganized AIG into three segments: General Insurance, Life and Retirement, and Blackboard Insurance—a technology-focused unit acquired from Hamilton’s U.S. business.

Early life and education

Born in Paget, Bermuda in 1947, Duperreault’s parents had separated before his birth. His mother relocated to Bermuda to be near a close companion before moving with her infant son to Trenton, New Jersey, where she worked as an accountant. Raised by a Catholic single mother, he attended Catholic schools and graduated in 1965 from St. Anthony High School (now Trenton Catholic Academy).

He obtained a B.S. degree in mathematics from Saint Joseph's University in Philadelphia in 1969. Beginning graduate studies in mathematics at the University of Maryland, College Park, his education was interrupted when he was drafted in November 1969. After completing one year under a deferment, he enlisted in the U.S. Army in 1970 and served three years stationed at Fort Knox, Kentucky.

Initially considering an academic career path, Duperreault shifted focus after marriage toward higher-paying opportunities. Upon military discharge, he explored career options and discovered the actuarial profession, which set him on the path toward insurance and risk management.

AIG 1973–1994

At age 26, shortly after completing military service, Duperreault joined AIG as an actuary in 1973. At that time, AIG was a mid-sized property-casualty insurer beginning its evolution under CEO Maurice R. Greenberg into a top global financial services company.

He progressed through various leadership roles including chief actuary (1978–1981), senior vice president of AIG subsidiary American Home Assurance (1981–1988), and chief casualty officer (1985–1987). Rising among AIG’s senior executives, he served as CEO of affiliates in Japan and Korea from 1989 to 1991. Between 1991 and 1994, he held the presidency of American International Underwriters, AIG’s international property-casualty division. In 1993 he assumed additional duties as executive vice president of AIG’s Foreign General Insurance operations; by 1994 he was promoted to chairman and CEO of American International Underwriters with oversight of all international business.

Viewed as a potential successor to Greenberg at AIG, Duperreault resigned after 21 years with the company in 1994 to take the helm at ACE Limited, one of its competitors.

ACE Limited

In October 1994, Duperreault assumed the roles of chairman, president, and CEO at ACE Limited, a specialized insurance firm headquartered in Bermuda with a workforce of 50. He swiftly broadened the company's scope and diversified its offerings through strategic acquisitions and the introduction of new insurance segments including satellite, financial lines, aviation, and excess property coverage. In 1996, he orchestrated the purchases of Tempest Re and the Lloyd's managing agencies Methuen and Ockham. The subsequent year, ACE formed a joint venture to establish Sovereign Risk Insurance, aimed at delivering political risk insurance on a global scale.

From 1998 to 1999, Duperreault managed several key acquisitions such as Tarquin plc, CAT Limited, Westchester Specialty Group, and most notably the Insurance Company of North America from CIGNA—the company's largest acquisition to date—alongside Capital Re Corporation. In 2001, he reorganized ACE into two primary divisions—ACE U.S. and Bermuda, and ACE International—each overseen by its own CEO. The following year, ACE secured a controlling interest in China's Huatai Insurance Company to collaboratively develop insurance products tailored for the Chinese market.

Under Duperreault’s guidance, ACE evolved from a niche insurer based in Bermuda into a global multi-line insurer and reinsurer employing over 9,000 people across 50 countries. He stepped down as CEO in May 2004 but continued serving as chairman of the board. His successor was Evan Greenberg, whom Duperreault had recruited from AIG in 2001 to lead Ace Tempest Re. Duperreault’s decade at the helm is credited with positioning Bermuda as a prominent international insurance center beyond its traditional reinsurance focus.

In September 2004, ACE recognized Duperreault’s contributions by establishing the Brian Duperreault Endowed Chair for Risk Management and Insurance at Saint Joseph's University. He retired from his role as non-executive chairman of ACE in May 2006.

Marsh & McLennan Companies

In January 2008, two years after retiring, Duperreault returned to lead New York-based global firm Marsh & McLennan Companies (MMC) as president and CEO. MMC ranks among the largest insurance brokers worldwide and was also a founding partner of ACE Limited. At that time, MMC was recovering from a bid-rigging scandal dating back to 2004 that resulted in an $850 million settlement and ongoing financial setbacks along with reputational harm including client losses and staff departures. The scandal—investigated by New York Attorney General Eliot Spitzer—involved manipulating bids and falsifying contracts to benefit insurers through inflated commissions. Additional difficulties facing MMC included excess market capacity, litigation challenges, organizational inefficiencies, low brokerage margins, and shareholder demands for corporate restructuring.

Duperreault initiated an urgent turnaround plan centered on divesting non-core assets and implementing significant workforce reductions to restore profitability. He restructured the executive leadership team, imposed strict expense controls, and assessed business alignment and synergies across operations. In 2008, he began divesting Kroll Inc.'s government services and mortgage data divisions while reorganizing Kroll's advisory segment; by 2010 MMC completed the full sale of Kroll for $1.13 billion.

In 2009, under his leadership MMC resolved investor lawsuits linked to the bid-rigging episode without admitting fault. He continued to simplify operations while pursuing growth through acquisitions of smaller firms. Additionally, he launched Marsh & McLennan Agency to target smaller and emerging U.S. businesses, significantly expanding it via acquisitions.

Duperreault was appointed to the U.S. Treasury's Federal Advisory Committee on Insurance in 2011 and became its inaugural chairman in 2012.

After five years as CEO of MMC, Duperreault retired on December 31, 2012. Throughout his tenure, he reduced costs and headcount, restored profitability and growth trajectories, rebuilt employee morale and corporate reputation, and regained trust among investors and clients. He also laid down a strategic framework ensuring MMC’s sustained success following his departure.

Hamilton Insurance Group

In 2013, driven by an interest in cutting-edge data analytics and data science applications within insurance, Duperreault collaborated with hedge fund Two Sigma Investments, known for its expertise in quantitative analysis, to establish Hamilton Insurance Group, assuming the role of CEO. The company specializes in utilizing advanced data analytics techniques in property-casualty insurance to enhance risk assessment and pricing strategies.

Hamilton's initial strategic move involved acquiring SAC Re, the reinsurance division of hedge fund SAC Capital Advisors based in Bermuda, which was subsequently renamed Hamilton Re, with Duperreault appointed as CEO. In January 2014, Sanford I. Weill, former head of Citigroup, was named Chairman of both Hamilton Insurance Group and Hamilton Re.

To create a balanced portfolio of insurance and reinsurance services, Hamilton broadened its footprint in the U.S. market by purchasing two insurance subsidiaries from Fairfax Financial Holdings in 2014, followed by the acquisition of Sportscover Underwriting in 2015—a managing agency with a Lloyd's syndicate—which was rebranded as Hamilton at Lloyd's. This expansion positioned Hamilton as a Bermuda-based holding company operating property and casualty insurance as well as reinsurance businesses throughout Bermuda, the United States, and the United Kingdom.

Weill retired from his Chairman position in February 2016, at which point Duperreault took over the role while continuing as CEO.

Later in 2016, Hamilton teamed up with AIG and Two Sigma to create Attune, an innovative platform leveraging data to sell commercial insurance online targeted at small and medium-sized enterprises, with Duperreault serving as chairman.

CEO and executive chairman of AIG

In May 2017, Brian Duperreault was appointed CEO of AIG following Peter Hancock’s March 2017 announcement to resign amid underwhelming financial performance. Since the 2008 financial crisis, AIG had divested numerous assets to repay its $185 billion U.S. government bailout but continued facing narrow profit margins, underwriting deficits, and challenges related to reputation and employee morale. Duperreault became the seventh individual to hold the CEO position within a span of 12 years.

Shortly after his appointment, AIG acquired Hamilton USA—later renamed Blackboard—and established a strategic reinsurance alliance with Hamilton Re. The Attune joint venture expanded its commercial insurance offerings to encompass larger enterprises. Additionally, AIG collaborated with Two Sigma to harness data science and technology advancements for underwriting commercial insurance on a global scale.

Duperreault introduced a growth-oriented strategy, shifting away from further divestitures or breakups. He reduced share repurchases in favor of acquiring smaller firms. By late 2017, federal regulators removed AIG’s designation as "too big to fail." Four months later, he led the acquisition of Bermuda-based Validus Holdings Ltd., enhancing AIG’s portfolio with reinsurance capabilities, a Lloyd’s syndicate, insurance-linked securities, U.S. small commercial excess and surplus lines underwriting, and crop insurance. This transaction also infused new underwriting expertise in property and catastrophe risk areas. In 2018, he further expanded AIG’s presence by purchasing Ellipse, a UK life insurer formerly owned by Munich Re.

During his inaugural year as CEO, Duperreault reorganized AIG into three divisions: General Insurance; Life and Retirement; and an independent technology unit named Blackboard Insurance—doing away with the prior commercial-consumer segmentation. He brought on board or promoted over a dozen senior executives along with 125 senior underwriters, including former associate Peter Zaffino as executive vice president and General Insurance CEO. Duperreault empowered division leaders with budgetary authority while granting underwriters increased decision-making latitude; he also enhanced workplace conditions to appeal to younger employees adept in technology. Cost reduction initiatives were implemented alongside leveraging economies of scale in supplier contracts and property expenses. The company-wide focus emphasized more prudent risk-taking within underwriting processes.

In February 2019, Duperreault identified previous losses as stemming from an overly aggressive "go large" approach that exposed the firm to excessive risk and volatility through multi-year contracts. His leadership team realigned risk exposures within General Insurance, repositioned private-client personal-insurance portfolios to mitigate catastrophe risks, invested in technology upgrades for Life and Retirement units, restructured organizational frameworks, re-underwrote existing business books, and revamped reinsurance procurement strategies.

By June 2019, AIG unified its reinsurance operations—including Validus Re, AlphaCat, and Talbot Treaty—into a consolidated global entity called AIG Re. In August 2019, the company reported underwriting profits for the second quarter running. That same month saw Duperreault and Zaffino launch "AIG 200," a three-year initiative aimed at streamlining operational workflows through digitization and integrating operations to reduce costs.

On January 1, 2020, Peter Zaffino assumed the role of AIG president succeeding Duperreault. Subsequently on March 1, 2021, Zaffino was promoted to CEO while Duperreault transitioned into the position of executive chairman of the board.

Memberships

Duperreault holds positions on the Board of Directors for AIG, the Geneva Association, and the Partnership for New York City. He participates in the Wall Street Journal CEO Council and serves on the Boards of Trustees at both Saint Joseph's University and the Bermuda Institute of Ocean Sciences (BIOS).

Honors and awards

• Bermuda Insurance Institute Market Leader of the Year (1998)
• Inducted into the Hall of Fame at Saint Joseph's University Haub School of Business (2002)
• Recognized as Insurance Leader of the Year by St. John's University School of Risk Management (2004)
• Recipient of the Lifetime Achievement Award from Bermuda Insurance Institute (2007)
• Conferred an Honorary Doctorate of Commercial Science by St. John's University (2006)
• Awarded an Honorary Doctor of Humanities degree from Saint Joseph's University (2008)
• Honored with the Business Achievement Award by Beta Gamma Sigma (2009)
• Named Insurance Broking CEO of the Year at Reactions magazine Global Market Awards (2011)
• Inducted into the Insurance Hall of Fame (2011)
• Presented with the Shield of Loyola Award from Saint Joseph's University (2011)
• Received the Distinguished Leadership Award from the Insurance Society of Philadelphia (2011)
• Ranked third among Top 25 Living Legends of Insurance by PropertyCasualty360 (2012)
• Listed as one of 24 Key Influencers in insurance by Best's Review (2016)
• Awarded North America Influential Individual of the Year by Reactions magazine (2017)
• Honored by the Harlem Educational Activities Fund (2018)

Philanthropy and outreach

Duperreault made a historic $10 million donation to his alma mater, Saint Joseph’s University, marking its largest single contribution to date. Additionally, he partnered with former U.S. President Jimmy Carter on philanthropic initiatives in China.

He has played a key role in advancing Bermuda’s nonprofit landscape, chairing organizations such as The Council Partners Charitable Trust, The Centre on Philanthropy, and the Bermuda Institute of Ocean Sciences (BIOS), among other community groups. In 2004, he founded the Duperreault Fellowship, an annual scholarship aimed at supporting professional growth for Bermuda residents specializing in substance abuse treatment. In 2013, he led Bermuda’s unpaid Spending and Government Efficiency (SAGE) Commission during its six-month tenure.

Duperreault has been a vocal advocate for workplace diversity, stressing the importance of addressing unconscious bias during recruitment processes. He has also focused extensively on combating gender bias within the insurance sector.

Since the mid-2010s, he has spearheaded efforts to engage Millennials in insurance careers by encouraging a more empathetic, communicative, and technologically adept industry environment—attributes that resonate strongly with younger professionals.

Personal life

Residing in the New York City metropolitan area with his wife Nancy, Duperreault is a father to three grown sons. He also serves as godfather to actress Elizabeth Tulloch.

He credits his professional achievements to his Jesuit education at Saint Joseph’s University and his deep spirituality. A committed Catholic, he has remarked, "It’s everything. It’s the essence of who I am. I try to pray for guidance all the time. It’s the best counsel you can seek." His faith played a significant role in guiding his leadership throughout Marsh & McLennan Companies’ recovery during periods of organizational and financial adversity.

External links

• Executive Profile at AIG