Worldwide, there are more than 95,000 private companies with annual revenues over US$100 million, compared to only 10,000 public companies over that threshold, according to a 2023 report from investment management firm Hamilton Lane. Private market assets grew to US$9.7 trillion in 2022, thanks to an increasing number of private equity funds and assets, up from about US$600 billion in 2000. And while private equity markets declined the past two years, McKinsey’s Global Private Markets Report for 2025 shows that a rebound is underway, with 30% of respondents saying they plan to increase their allocations. 

Historically, private companies are more, well, private. They don’t have the same regulatory requirements to disclose information that public companies do, especially when it comes to revenues and profits. But with sustainability, there are reasons to be more forthcoming. Private companies are increasingly eager to report on their environmental, social and governance (ESG) performance and their sustainability investments amid the public’s growing appetite for companies that are trying to be good corporate citizens. For example, a McKinsey study found that products making ESG-related claims grew on average 8% faster than those that don’t.

It’s these companies that Corporate Knights has chosen to focus on in its inaugural Private 25 Most Sustainable Corporations ranking.

Private companies can play an outsized role in setting the pace of the sustainability transition.

-Toby Heaps, co-founder and CEO of Corporate Knights

Toby Heaps, co-founder and CEO of Corporate Knights, says the ranking was a natural next step, given how eager many companies are to report on their ESG progress. “The really interesting thing about privately held companies is that their governance creates more space to make big bets and pivot to the future – in this case a sustainable future,” Heaps says.

The global list includes companies in a range of industries, from consumer goods and transportation to forest products, energy and power distribution. Companies in Europe and the United Kingdom dominate the ranking, although a few are from Canada. No U.S. companies are on the list, which Heaps says could be due to liability concerns: “U.S. corporate disclosure is subpar for public companies, and this holds for private companies as well.”

The ranking includes key performance indicators (KPIs) in areas such as energy, water, and waste, and governance factors like gender diversity. It also includes sustainable revenue and investment categories. 

The top-ranked companies scored high on sustainable KPIs and revenue/investment. For example, the first-place Netherlands-based Accell Group, which makes bicycles, e-bikes and parts and accessories, scored 100% in both the investment and revenue categories. It also scored 70% in both energy productivity and carbon productivity.

Heaps says the new annual ranking is a benchmark for private companies to improve their sustainability practices and gives consumers more information about what brands are doing to help society and the planet. “Because of their governance structure, private companies can play an outsized role in setting the pace of the sustainability transition – and this ranking shows which companies are leading the way.”

1. Accell Group NV

Purpose-driven bicycle maker

Netherlands-based Accell Group makes bicycles and e-bikes that are sold in more than 80 countries. Its stable of brands includes Haibike, Raleigh and Babboe. The purpose-driven company says it doesn’t just build bikes: “We’re creating experiences that move the world forward,” supporting healthy citizens, livable cities and a healthier environment. “We are convinced that sustainable production and products will ultimately add value to our company, which will in turn create new opportunities.”

2. Dolomiti Energia Holding SpA

Italian renewables powerhouse

Dolomiti Energia Holding is an Italy-based company that distributes electricity, natural gas, heat and water through its multiple subsidiaries. It also has business in electric mobility and environmental services. The company says it generates an average of almost 4,000 gigawatt hours of electricity, 98% from certified renewable sources, mostly hydroelectric power. It also says it has installed capacity of around 28 megawatts of wind power and is developing photovoltaic plants with a planned capacity of approximately 58 MW.

3. Amprion GmbH  

Grid transition enabler

Amprion is one of four transmission system operators in Germany. Its 11,000-kilometre-long high-voltage network transports electricity from the North Sea to the Alps, covering a population of 29 million people. Amprion says it’s “paving the way” for Europe’s energy transition to provide a climate-neutral, safe, secure and efficient energy system. A new project to transport wind energy to the Ruhr region “will make an important contribution to the security of supply in Germany and Europe in the future” as early as 2030, Amprion CTO Hendrik Neumann says.

4. Adevinta ASA

Circular-consumption champion

Norway-based Adevinta is an online classifieds group behind many popular digital marketplaces: Kijiji in Canada, leboncoin in France and Subito in Italy, among others. Through these platforms, Adevinta promotes “circular consumption” for individuals and businesses worldwide. The company’s “second-hand effect” conserves energy and raw materials, reduces greenhouse gases and minimizes waste. 

5. Oesterreichische Kontrollbank AG

Sustainable development bank

Oesterreichische Kontrollbank (OeKB) – or Austrian Control Bank – is a special-purpose financial institution owned by Austria’s main banks. Part of its activity is carried out on behalf of the Austrian government and backed by the state budget. OeKB focuses on five service areas: export, capital markets, energy markets, development financing and tourism. Its development bank provides concessional loans, or so-called soft loans, for sustainable projects that are implemented by Austrian companies in less developed countries. “Orientation towards the [UN] Sustainable Development Goals is a lived reality at OeKB,” board member Angelika Sommer-Hemetsberger says. 

6. Énergir 

Greening power distributor

Énergir is a Canada-based distributor of renewable and conventional gas, solar and wind power, and hydroelectricity for 525,000 customers in Quebec and Vermont. Last year, it attracted $575 million in investments to help it roll out its decarbonization plan and announced that all new customers will be powered by 100% renewable energy. “We have made promising commitments for the future, further extending our willingness to be part of the solution,” president and CEO Éric Lachance said.

7. BGIS

Eco-friendly facilities management

Heating and cooling buildings accounts for about 33% of greenhouse gas emissions globally, which is why driving down those emissions is central to BGIS (Brookfield Global Integrated Solutions) – a Canada-based facilities management and real estate services company. The company promotes sustainable practices that reduce energy use, conserve water and reduce waste. “On an annual basis, we identify 15,000 metric tons of [carbon dioxide equivalent] savings for our clients,” BGIS says.

8. Heathrow SP Ltd

Pursuing low-carbon air travel

Flying is notoriously carbon intensive, but Heathrow SP Ltd., the company behind London’s Heathrow Airport, is working on cutting up to 15% carbon “in the air” by 2030 (using waste-based aviation fuels) and at least 45% carbon “on the ground” by 2030. Since 2019, it has cut air carbon by 7.5% and ground carbon by 15%. “Even during a traditionally quiet month for aviation in February, we saw sustained and growing demand to fly and export through Heathrow,” CEO Thomas Woldbye says. “Reaching net-zero as we grow remains vital.”

9. Motability Operations

Electrified mobility backer

London-based Motability Operations runs the Motability Scheme, a U.K. program to help people with disabilities lease new cars, scooters or powered wheelchairs. The company aims to achieve net-zero emissions by 2050, in line with the Paris Agreement, largely by helping its customers switch to electric vehicles. The company says it has transitioned more than 70,000 customers to date. It is also helping to address barriers to shifting to EVs by covering the cost of insurance and servicing and by providing a charging card that facilitates powering up at more than 50,000 charge points. 

10. Go-Ahead Group Ltd

Net-zero-aligned transporter

Go-Ahead is a U.K.-based bus and rail operator for public transport. It runs a fleet of more than 6,000 electric buses across England and a quarter of the buses for London’s transport network. Internationally, the company operates buses in Singapore, Ireland, Sweden and Australia, as well as rail franchises in the United Kingdom, Sweden and Norway. Go-Ahead aims to become a net-zero business by 2045 and has outlined clear milestones along the way, including decarbonizing its bus fleet and eliminating all remaining diesel trains from its networks by 2035.

11. Kruger Products Inc

Responsible paper products

Kruger Products is a maker of well-known tissue, paper and packaging products such as Scotties, Purex and Sponge Towels. The Canadian company says it recycles thousands of tonnes of paper and paperboard and works to reduce greenhouse gas emissions at its plants across North America. The company says it is committed to sourcing only third-party certified fibre and has a large portfolio of offerings certified by the Forest Stewardship Council.

12. Biffa PLC

Conscientious waste management

U.K.-based Biffa is an integrated waste-management business that also provides technology-driven energy-generation services for commercial, industrial and public-sector customers throughout the United Kingdom. Biffa has a partnership with Company Shop Group to collect and redistribute surplus food. The company also does environmental work with WasteAid, an independent charity working with communities in low-income countries to share simple, low-cost ways to cut back on waste. Biffa says it has reduced carbon emissions by 70% since 2002 and aims to be net-zero by 2050. 

13. Voith GmbH & Co KGaA

Industrial sustainability leader

The Voith Group is a major Germany-based technology company operating in the energy, paper, raw materials, transport and automotive sectors. Voith’s biggest sustainable claim to fame: a quarter of the energy generated worldwide from hydropower is produced with turbines and generators from Voith Hydro. “Industrial sustainability is our business model,” former CEO Toralf Haag said. “In this way, we make a decisive contribution to a climate-neutral industry and at the same time secure our growth.” Jan Lüder, incoming CEO of Voith Hydro, is poised to grow the company’s hydro operations to capitalize on the growth opportunities of the global energy transition.

14. Tod’s SpA

Conscious Italian footwear

The Tod’s Group is an Italian luxury footwear, leather goods and clothing company, behind its brands Tod’s, Roger Vivier, Hogan and Fay. The company says that 100% of its energy for its Italian operations comes from renewable sources and that about 6,000 recovered leather goods and linings were included in upcycling projects. It also aims for gender diversity: 58% of managers are women. It has a particular interest in fostering the local economy, with 99% of its raw materials for its Italian operations purchased from local suppliers.

15. Robert Bosch GmbH 

Sustainable tech solutions

The Bosch Group is a Germany-based technology and services company best known for its appliances, but it also has activities in mobility, industrial technology, and energy and building technology. By 2023, Bosch reported that 99% of its electricity requirements were met by green energy. The company says that it plans to spend more than a billion euros on heat-pump technology and that it will invest roughly €2.5 billion in hydrogen technologies between 2021 and 2026. It has committed to investing €1 billion to increasing energy efficiency by 2030.

16. Sofidel SpA

Low-impact paper producer

Italy-based Sofidel is a global manufacturer of tissue paper whose best-known brand is Regina. The company has committed to reaching net-zero carbon emissions by 2050. Some of the actions underway include using new technologies to boost energy efficiency, moving to electrification, and using more renewable energy, bio-based fuels and green hydrogen. The company has also committed to employing more forest management practices, reusing and reducing packaging with renewable materials, and exploring carbon-removal technologies. 

17. Ikea

Eco-savvy furniture maker

Founded in 1943, popular home-furnishing company Ikea has committed to halving its value-chain emissions by 2030 and reaching net-zero by 2050. The company says it has already shrunk its total climate footprint by 22% compared to 2016 – with half those reductions made in the last year alone. The company is focusing on using only “responsibly sourced renewable or recycled materials.” More than 9,500 of its products have been assessed for circularity, and more than 23 million assembly parts were offered to customers in 2023 to extend the life of their products. 

18 Topsoe A/S

Carbon-reduction innovator

Denmark-based Topsoe, founded in 1940, makes emission-reduction technologies, helping to turn renewable resources into fuels and chemicals. Some of its early technologies included solutions to reduce sulfur and other pollutants from fossil fuel emissions to environmentally safe levels. Today, its products support the energy transition by using feedstock and used cooking oil to decarbonize fuel. Some of its recent projects include lending its technology to China’s Chuangui New Energy company to help it avoid an estimated 800,000 tons of carbon dioxide equivalent by using sustainable aviation fuels and renewable diesel.

19. Assemblin Caverion Group AB 

Smart building services

Sweden-based Assemblin Caverion Group is a northern and central European technical-service and -installation company formed in 2024 from the merger of Assemblin and Caverion. Its main activities include building services such as mechanical, electrical, plumbing, HVAC and building automation, as well as smart technologies and digital solutions. In 2023, Assemblin boosted its proportion of electric and hybrid vehicles to 24% and decreased its carbon footprint per employee by 6.7%. 

20. Domtar Corp (formerly Paper Excellence Group)

Paper products powered by renewables

Paper Excellence Group is a forest-products company rebranded as Domtar Corp. in 2024. Domtar has dual headquarters in the United States and Canada, and it produces more than nine million tonnes of pulp, paper, packaging and tissue and about three billion board feet of lumber and other wood products. The company’s 2023 sustainability report says that it used 66% renewable energy in its pulp and paper mills and that 59% of the electricity in its mills was self-generated. 

21. Tetra Pak AB

Packaging innovator 

Switzerland-based Tetra Pak, known for its food and beverage packaging, also makes processing equipment, filling machines, distribution equipment and spare parts. The company says it used 89% renewable energy across its operation in 2023 and reduced emissions across its value chain by 20% compared to its 2019 baseline. Tetra Pak gets 6% of its revenue from making plant-based packaging and has plowed roughly one-third of its investments into collection and recycling projects, as well as solar power. 

22. Lego A/S

Greener toys 

The Lego Group is the company behind the famous Lego bricks. Based in Denmark, with manufacturing facilities worldwide, the company has a target to reduce  emissions by 37% by 2032, compared to 2019, and achieve net-zero emissions by 2050. That means reducing waste and water usage and eliminating single-use plastic from all its products. The company says that in 2025 it will have doubled its spending on sustainable initiatives compared to 2023. In February, it announced it was introducing Lego pieces containing recycled materials from engine oil and fishing nets.

23. ContourGlobal Ltd 

Transition-forward power producer

U.K.-based ContourGlobal is an independent power producer that manages about 6.2 gigawatts of installed capacity in 18 countries. Its sustainability strategy covers four areas: decarbonization, performance optimization, development and partnership growth, and portfolio innovation in emerging clean technologies. The company recently closed a green bond offering that will help it transition to predominantly renewable sources of power. To do that, it’s working on accelerating renewable-energy development and scaling up battery storage.

24. Imperial Logistics Ltd

Responsible logistics

Imperial Logistics provides logistics and supply-chain management services across industries, mostly in Africa and Europe. Its supply-chain control-tower services leverage data analytics and automation to improve efficiency throughout supply chains. Imperial is also piloting more efficient truck technologies and working to reduce water consumption and manage hazardous chemicals and waste. In 2022, Imperial became a wholly owned business of DP World.

25. Celulosa Arauco y Constitución

Ethically produced paper 

Also known as Celco or Arauco, Celulosa is a Chilean wood, pulp, engineered wood and forestry company. It says it is the first forestry company in the world to be certified as carbon-neutral. It uses cellulose and the pulp of pine and eucalyptus trees to produce sustainable fibres for textiles, packaging products, hygiene products such as diapers, and a wide range of engineered wood planks. In its 2023 sustainability report, the company said that it had planted 131.6 million trees in Chile, Argentina, Brazil and Uruguay, harvested 19.7 million and purchased 6.5 million cubic metres of timber.

Brenda Bouw is a freelance writer and editor based in Vancouver.

Read more: The 2025 Public 25 most sustainable public-sector companies in the world

*N/A: Not applicable. Banks, asset management and insurance peer groups are not assessed on the sustainable investment KPI. The weight of this KPI has been reweighted to the sustainable revenue KPI.

Methodology

Our methodology for the new Corporate Knights Private 25 and Public 25 rankings uses a mix of fixed- and variable-weight ESG and sustainable-economy KPIs to score companies against their peers. We measure the share of revenues and investments that are included in the Corporate Knights Sustainable Economy Taxonomy and percent rank those ratios against the company’s CKPG (Corporate Knights Peer Group). We then give equal weight to the ratios and the percent ranks in awarding up to 25 points for sustainable revenue and up to 25 points for sustainable investment, for a total of 50 possible points.

The other 50 points are allocated to 10 ESG KPIs, including productivities for energy, carbon, waste and water, along with board and executive gender and racial diversity, taxes paid and injury rate. In addition, penalties are levied against overall scores for a number of factors, including injuries and fatalities.

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