Meet our team

Robert Mah | President and Co-Founder

Rob is a Co-Founder and leads the efforts of the Guardian Smart Infrastructure Management’s (GSIM) team on behalf of its investors and partners. Rob chairs the investment Committee for the Guardian Smart Infrastructure Partners funds. Rob has over 30 years of investment industry experience – 20 years as an investment banker with global investment banks and over a decade and a half of experience managing private investments for large institutional and private investors. Rob’s experience spans many sectors, including energy, materials, transportation, infrastructure, private equity and real estate.

Before co-founding GSIM, Rob was EVP and Head of Private Investments for one of Canada’s largest pension funds, where his teams consistently exceeded their clients’ investment benchmarks. In his role as an investment banker, Rob had progressive roles leading investment banking teams in London, New York and Toronto. Concurrently, Rob served as a Senior Advisor to BCG’s Principal Investors and Private Equity Group.

Rob served recently on the Boards of two charitable organizations in Canada. He served as the former Chair of a Children’s foundation and Head of the Investment Committee of an Endowment Fund for a girls’ school.

Rob holds a bachelor's degree specializing in Finance and Economics from McGill University and a master’s degree in business administration from the University of Toronto’s Rotman School of Management.

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Robert Mah
President and Co-Founder

Rob is a Co-Founder and leads the efforts of the Guardian Smart Infrastructure Management’s (GSIM) team on behalf of its investors and partners. Rob chairs the investment Committee for the Guardian Smart Infrastructure Partners funds. Rob has over 30 years of investment industry experience – 20 years as an investment banker with global investment banks and over a decade and a half of experience managing private investments for large institutional and private investors. Rob’s experience spans many sectors, including energy, materials, transportation, infrastructure, private equity and real estate.

Before co-founding GSIM, Rob was EVP and Head of Private Investments for one of Canada’s largest pension funds, where his teams consistently exceeded their clients’ investment benchmarks. In his role as an investment banker, Rob had progressive roles leading investment banking teams in London, New York and Toronto. Concurrently, Rob served as a Senior Advisor to BCG’s Principal Investors and Private Equity Group.

Rob served recently on the Boards of two charitable organizations in Canada. He served as the former Chair of a Children’s foundation and Head of the Investment Committee of an Endowment Fund for a girls’ school.

Rob holds a bachelor's degree specializing in Finance and Economics from McGill University and a master’s degree in business administration from the University of Toronto’s Rotman School of Management.

Christopher Lee | Operating Partner and Co-Founder

Chris is a Co-Founder and Operating Partner of Guardian Smart Infrastructure Management (GSIM). He was most recently a Partner with Smart Infrastructure Managers (now part of Guardian Smart Infrastructure). Chris was the Founder and former Managing Partner of Highstar Capital, an infrastructure investment firm he founded in 2000 and sold to Oaktree Capital in 2014. Through four funds, Highstar managed $7.8 billion in assets. Chris sourced, procured, structured and financed a number of successful P3 projects in the US (including the award-winning Seagirt Marine Terminal in the Port of Baltimore and Luis Munoz San Juan Puerto Rico Airport projects). More recently, Chris has advised on the formation of a digital private equity fund with Cisco. Chris and Rob worked together in a portfolio manager/LP/co-investor capacity at Highstar and AIMCo, respectively. Chris has a BA in History from the Johns Hopkins University, where he served as a trustee and member of the Finance Committee for six years, including as Chair of the Debt Committee – where he oversaw a successful refinancing of substantially all of the University’s long-term obligations, enhancing the average life and improving the cost of financing.

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Christopher Lee
Operating Partner and Co-Founder

Chris is a Co-Founder and Operating Partner of Guardian Smart Infrastructure Management (GSIM). He was most recently a Partner with Smart Infrastructure Managers (now part of Guardian Smart Infrastructure). Chris was the Founder and former Managing Partner of Highstar Capital, an infrastructure investment firm he founded in 2000 and sold to Oaktree Capital in 2014. Through four funds, Highstar managed $7.8 billion in assets. Chris sourced, procured, structured and financed a number of successful P3 projects in the US (including the award-winning Seagirt Marine Terminal in the Port of Baltimore and Luis Munoz San Juan Puerto Rico Airport projects). More recently, Chris has advised on the formation of a digital private equity fund with Cisco. Chris and Rob worked together in a portfolio manager/LP/co-investor capacity at Highstar and AIMCo, respectively. Chris has a BA in History from the Johns Hopkins University, where he served as a trustee and member of the Finance Committee for six years, including as Chair of the Debt Committee – where he oversaw a successful refinancing of substantially all of the University’s long-term obligations, enhancing the average life and improving the cost of financing.

Jonathan Stone | Managing Director

Jonathan is a member of the GSIM investment team, responsible for identifying and sourcing investment opportunities, structuring and negotiating deals, and driving value creation in portfolio companies. He has over 25 years of experience in the infrastructure industry, focusing on transportation and energy. Jonathan's expertise spans construction, corporate and project finance, public-private partnerships and mergers and acquisitions.

Prior roles include Partner at Instar Asset Management, where he built an infrastructure equity portfolio of transportation and energy investments, and Managing Director at Scotiabank, leading the EMEA Infrastructure and Energy division. He also held senior positions at Plenary Group and CIT, focusing on PPP projects in North America.

Jonathan holds a Bachelor of Engineering Degree (Civil) from McGill University, an MBA from Cambridge University and is a CFA® Charterholder.

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Jonathan Stone
Managing Director

Jonathan is a member of the GSIM investment team, responsible for identifying and sourcing investment opportunities, structuring and negotiating deals, and driving value creation in portfolio companies. He has over 25 years of experience in the infrastructure industry, focusing on transportation and energy. Jonathan's expertise spans construction, corporate and project finance, public-private partnerships and mergers and acquisitions.

Prior roles include Partner at Instar Asset Management, where he built an infrastructure equity portfolio of transportation and energy investments, and Managing Director at Scotiabank, leading the EMEA Infrastructure and Energy division. He also held senior positions at Plenary Group and CIT, focusing on PPP projects in North America.

Jonathan holds a Bachelor of Engineering Degree (Civil) from McGill University, an MBA from Cambridge University and is a CFA® Charterholder.

Laura Ryan | Chief Financial Officer/Chief Compliance Officer

Laura is the Chief Financial Officer and Chief Compliance Officer for Guardian Smart Infrastructure Management (GSIM). Laura has over 15 years of experience in the financial services sector. Before GSIM, Laura worked in the finance group for Guardian Capital Group Limited (Guardian) with a primary focus on acquisitions, investor relations and corporate development. Prior to Guardian, Laura worked for 12 years in the audit practice at KPMG LLP, covering pension funds, financial institutions, and real estate clients. Laura is responsible for GSIM’s dedicated compliance process.

Laura is a Chartered Professional Accountant (CA) and earned a Bachelor of Commerce Degree from Dalhousie University.

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Laura Ryan
Chief Financial Officer/Chief Compliance Officer

Laura is the Chief Financial Officer and Chief Compliance Officer for Guardian Smart Infrastructure Management (GSIM). Laura has over 15 years of experience in the financial services sector. Before GSIM, Laura worked in the finance group for Guardian Capital Group Limited (Guardian) with a primary focus on acquisitions, investor relations and corporate development. Prior to Guardian, Laura worked for 12 years in the audit practice at KPMG LLP, covering pension funds, financial institutions, and real estate clients. Laura is responsible for GSIM’s dedicated compliance process.

Laura is a Chartered Professional Accountant (CA) and earned a Bachelor of Commerce Degree from Dalhousie University.

Pieter Quartero | Principal

Pieter is a Principal for Guardian Smart Infrastructure Management (GSIM). Pieter joined GSIM in 2022 with the founding partners, having joined Smart Infrastructure Managers (now part of Guardian Smart Infrastructure) in 2020 to assist with investment due diligence and deal screening. Before this role, Pieter worked closely with Rob Mah and Kevin Roseke at AIMCo since 2015 as an Associate in the Infrastructure Group, where he investigated and screened numerous investment opportunities in a wide variety of infrastructure sub-sectors including telecommunications, fibre, energy storage, ports, toll roads, pipelines, renewable energy, and utilities. Pieter’s investment experience covers a global basis, with transactions in the US, UK, Europe, and South America. Before AIMCo, Pieter worked as an investment banker at BMO Capital Markets in Calgary, Alberta, from 2010 to 2014. While at BMO, he worked on numerous financing and M&A engagements, largely in the energy infrastructure space.

Pieter holds degrees in Political Science from the University of Alberta and in Finance and Economics from the University of Calgary.

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Pieter Quartero
Principal

Pieter is a Principal for Guardian Smart Infrastructure Management (GSIM). Pieter joined GSIM in 2022 with the founding partners, having joined Smart Infrastructure Managers (now part of Guardian Smart Infrastructure) in 2020 to assist with investment due diligence and deal screening. Before this role, Pieter worked closely with Rob Mah and Kevin Roseke at AIMCo since 2015 as an Associate in the Infrastructure Group, where he investigated and screened numerous investment opportunities in a wide variety of infrastructure sub-sectors including telecommunications, fibre, energy storage, ports, toll roads, pipelines, renewable energy, and utilities. Pieter’s investment experience covers a global basis, with transactions in the US, UK, Europe, and South America. Before AIMCo, Pieter worked as an investment banker at BMO Capital Markets in Calgary, Alberta, from 2010 to 2014. While at BMO, he worked on numerous financing and M&A engagements, largely in the energy infrastructure space.

Pieter holds degrees in Political Science from the University of Alberta and in Finance and Economics from the University of Calgary.

Cameron Santoni | Principal

Cameron Santoni joins Guardian with nine years of experience in infrastructure investment, spanning principal investing, investment banking, and renewable energy development. Most recently, he served as Associate Director at CVC DIF, where he supported transaction origination and execution across North America within the firm’s core and core+ fund strategies. In this role, Cameron led acquisitions and full lifecycle asset management across multiple infrastructure sectors.

Prior to CVC DIF, Cameron held roles in the Infrastructure and Power Investment Banking group at BMO Capital Markets, advising on and financing large-scale infrastructure and renewable energy projects. His introduction to the sector began during university through internships in solar and renewable natural gas development, providing early hands-on experience that shaped his career trajectory.

Cameron holds an Honours Business Administration (HBA) degree from the Ivey Business School.

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Cameron Santoni
Principal

Cameron Santoni joins Guardian with nine years of experience in infrastructure investment, spanning principal investing, investment banking, and renewable energy development. Most recently, he served as Associate Director at CVC DIF, where he supported transaction origination and execution across North America within the firm’s core and core+ fund strategies. In this role, Cameron led acquisitions and full lifecycle asset management across multiple infrastructure sectors.

Prior to CVC DIF, Cameron held roles in the Infrastructure and Power Investment Banking group at BMO Capital Markets, advising on and financing large-scale infrastructure and renewable energy projects. His introduction to the sector began during university through internships in solar and renewable natural gas development, providing early hands-on experience that shaped his career trajectory.

Cameron holds an Honours Business Administration (HBA) degree from the Ivey Business School.