# Top 30 corporate groups and holding companies in London

Tamtam tracks 210 corporate groups and holding companies headquartered in London. This list ranks the 30 largest by number of employees on LinkedIn, led by RELX, Balfour Beatty plc and Smollan. Their median headcount is 3,140. Half of them were founded in 1982 or later.

This list comprises corporate groups and holding companies based in London. These firms represent a range of sectors, including technology, construction, and healthcare. Notably, RELX is a global provider of information-based analytics, Balfour Beatty plc is an infrastructure group, Smollan partners with brands and retailers, and Informa is an international business in events and digital services. Acacium Group provides healthcare delivery, and KELLER specializes in geotechnical contracting.

The companies on this list are predominantly large groups. Several, such as Balfour Beatty plc, founded in 1909, and Coats, established in 1755, have long histories, indicating a presence of established enterprises within London's corporate landscape.

🇬🇧 London · 30 companies · Updated Nov 12, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [RELX](https://www.tamtam.ai/c/relx) (relx.com)<br>Global provider of information-based analytics for professionals across industries, helping customers make informed decisions through innovative solutions and technologies | Technology, Information and Media | 🇬🇧 London | 37,600 |  |
| 2 | [Balfour Beatty plc](https://www.tamtam.ai/c/balfour-beatty-plc) (balfourbeatty.com)<br>A global infrastructure group with 25,000 employees delivering innovative and efficient transportation, power, building, and utility systems for economic growth and community support | Construction | 🇬🇧 London | 25,000 | 1909 |
| 3 | [Smollan](https://www.tamtam.ai/c/smollan) (smollan.com)<br>Partners with brands and retailers, building solutions that drive growth and create opportunities at the point of purchase. | Retail | 🇬🇧 London | 13,502 | 1931 |
| 4 | [Informa](https://www.tamtam.ai/c/informa) (informa.com)<br>Leading international business in events, digital services, and academic knowledge, connecting specialists worldwide to learn, know, and do more in their fields | Information Services | 🇬🇧 London | 9,410 | 1998 |
| 5 | [SThree](https://www.tamtam.ai/c/sthree) (sthree.com)<br>Connecting skilled STEM professionals with organizations to drive innovation and solve complex challenges through specialist brands and tailored workforce solutions. | Business Consulting and Services | 🇬🇧 London | 7,927 |  |
| 6 | [Acacium Group](https://www.tamtam.ai/c/acacium-group) (linktr.ee)<br>Global healthcare delivery partner with 40+ years experience offering workforce access, technology, and expertise to improve healthcare, social care, and life sciences worldwide | Hospitals and Health Care | 🇬🇧 London | 5,961 |  |
| 7 | [KELLER](https://www.tamtam.ai/c/keller) (keller.com)<br>A global geotechnical specialist contractor that solves construction challenges with local focus, expertise, and a track record of successful projects | Construction | 🇬🇧 London | 5,930 |  |
| 8 | [Coats](https://www.tamtam.ai/c/coats) (coats.com)<br>A global leader in thread manufacturing and performance materials, providing innovative, sustainable solutions for apparel, footwear, and other industries worldwide | Textile Manufacturing | 🇬🇧 London | 5,122 | 1755 |
| 9 | [Cygnet](https://www.tamtam.ai/c/cygnet) (cygnetgroup.com)<br>Providing health and social care services for individuals with mental health needs, brain injuries, eating disorders, autism, and learning disabilities in the UK. | Hospitals and Health Care | 🇬🇧 London | 4,847 | 1988 |
| 10 | [RSS Global](https://www.tamtam.ai/c/rss-global) (rssglobal.com)<br>A portfolio of staffing brands specializing in workforce solutions across various sectors in the UK, Ireland, and Asia Pacific | Staffing and Recruiting | 🇬🇧 London | 4,535 |  |
| 11 | [Murphy](https://www.tamtam.ai/c/murphy) (murphygroup.com)<br>Provides engineering and construction services across transportation, water, power, natural resources, and property sectors in UK, Ireland, and Canada. | Civil Engineering | 🇬🇧 London | 4,078 | 1951 |
| 12 | [Noventiq](https://www.tamtam.ai/c/noventiq) (noventiq.com)<br>A global digital transformation and cybersecurity solutions provider connecting 80,000+ organizations, with a diverse portfolio and active M&A strategy for growth | IT Services and IT Consulting | 🇬🇧 London | 3,941 |  |
| 13 | [Places for People](https://www.tamtam.ai/c/places-for-people) (placesforpeople.co.uk)<br>It is a leading social enterprise in the UK, focusing on community development, housing, leisure, and social impact initiatives. | Real Estate | 🇬🇧 London | 3,935 |  |
| 14 | [Endeavour Mining](https://www.tamtam.ai/c/endeavour-mining) (endeavourmining.com)<br>Senior gold producer operating mines and development projects across West Africa, focusing on responsible mining and sustainable community value. | Mining | 🇬🇧 London | 3,594 | 2010 |
| 15 | [City & Guilds](https://www.tamtam.ai/c/city-and-guilds) (cityandguilds.com)<br>Providing comprehensive skills training, credentials, and workforce development solutions through a global network to support employment and career growth. | Education | 🇬🇧 London | 3,140 | 1878 |
| 16 | [London South Bank University](https://www.tamtam.ai/c/london-south-bank-university) (lsbu.ac.uk)<br>Provides engaging courses, industry connections, and real-world experience to empower diverse students to unlock their potential for success in work and life | Higher Education | 🇬🇧 London | 3,080 | 1892 |
| 17 | [Stolt-Nielsen](https://www.tamtam.ai/c/stolt-nielsen) (stolt-nielsen.com)<br>Global provider of bulk-liquid and chemical logistics, transportation, storage services, and innovative sustainable aquaculture producing premium seafood species. | Transportation, Logistics, Supply Chain and Storage | 🇬🇧 London | 3,069 | 1959 |
| 18 | [DMGT](https://www.tamtam.ai/c/dmgt) (dmgt.com)<br>Management of companies delivering information, analysis, insight, events, news, and entertainment to businesses and consumers with market leadership. | Information Services | 🇬🇧 London | 3,022 |  |
| 19 | [Sumer](https://www.tamtam.ai/c/sumer) (sumer.co.uk)<br>Championing small to medium UK and Ireland businesses by uniting expert firms to provide collaborative support and growth solutions. | Accounting | 🇬🇧 London | 2,608 |  |
| 20 | [Blenheim Chalcot](https://www.tamtam.ai/c/blenheim-chalcot) (blenheimchalcot.com)<br>A venture builder investing in high-growth sectors by providing funds, expertise, and infrastructure to build profitable, scalable companies globally | Technology, Information and Internet | 🇬🇧 London | 2,370 | 1998 |
| 21 | [Hachette UK](https://www.tamtam.ai/c/hachette-uk) (hachette.co.uk)<br>Publishing diverse books including fiction, non-fiction, children's books, educational materials, puzzles, gifts, games, e-books, and audiobooks globally. | Book and Periodical Publishing | 🇬🇧 London | 2,219 |  |
| 22 | [Aptia Group](https://www.tamtam.ai/c/aptia-group) (aptia-group.com)<br>Professional services firm combining technology and expertise to simplify pensions, health, and insurance management for businesses and individuals globally. | Professional Services | 🇬🇧 London | 2,209 | 2023 |
| 23 | [Zen Educate](https://www.tamtam.ai/c/zen-educate) (zeneducate.com)<br>This company is revolutionizing education recruitment by saving schools money on agency fees, providing skilled staff, and offering a user-friendly online platform | Education Administration Programs | 🇬🇧 London | 2,147 | 2017 |
| 24 | [ED&F Man Commodities](https://www.tamtam.ai/c/ed-and-f-man-commodities) (edfman.com)<br>Global provider of agricultural commodities including coffee, sugar, molasses, animal feeds, and fish oil with strong sustainability focus. | International Trade and Development | 🇬🇧 London | 2,142 | 1783 |
| 25 | [Shaw Trust](https://www.tamtam.ai/c/shaw-trust) (shawtrust.org.uk)<br>A social purpose organization focused on challenging inequality, providing employment opportunities, and supporting social mobility through various services and support | Non-profit Organizations | 🇬🇧 London | 2,124 | 1982 |
| 26 | [Collinson Group](https://www.tamtam.ai/c/collinson-group) (collinsongroup.com)<br>Global company specializing in travel solutions, airport experiences, loyalty programs, insurance, and customer engagement for millions of consumers worldwide | Consumer Services | 🇬🇧 London | 2,108 | 1989 |
| 27 | [Clarion Housing Group](https://www.tamtam.ai/c/clarion-housing-group) (clarionhg.com)<br>providing affordable homes to 360,000 people, building new homes annually, supporting residents through charitable programs focused on work, neighborhoods, and sustainability | Real Estate | 🇬🇧 London | 2,038 | 2016 |
| 28 | [Urenco Global](https://www.tamtam.ai/c/urenco-global) (urenco.com)<br>Supplier of nuclear fuel enrichment services using centrifuge technology, ensuring safe, reliable, and sustainable nuclear fuel supply globally. | Utilities | 🇬🇧 London | 2,027 | 1970 |
| 29 | [London Borough of Barking and Dagenham](https://www.tamtam.ai/c/london-borough-of-barking-and-dagenham) (lbbd.gov.uk)<br>A growing London borough investing in physical infrastructure, community, housing, a film studio, a university campus, and a Youth Zone Visit website for more information | Government Administration | 🇬🇧 London | 2,002 | 1965 |
| 30 | [10N Collective](https://www.tamtam.ai/c/10n-collective) (10ncollective.com)<br>Global collective of urbanism, architecture, and design experts focused on sustainable citymaking, environmental and social responsibility across continents. | Architecture and Planning | 🇬🇧 London | 1,735 | 2025 |

## How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 12, 2026.

## More company lists in London

- [The largest companies in London](https://www.tamtam.ai/l/largest-companies-london) (12,882)
- [Multinational companies in London](https://www.tamtam.ai/l/multinational-companies-london) (3,652)
- [Financial Services companies in London](https://www.tamtam.ai/l/financial-services-companies-london) (1,862)
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- [Software Development companies in London](https://www.tamtam.ai/l/software-development-companies-london) (1,217)
- [Retail chains in London](https://www.tamtam.ai/l/retail-chains-london) (942)
- [IT Services and IT Consulting companies in London](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-london) (693)
- [Companies with a mobile app in London](https://www.tamtam.ai/l/companies-with-mobile-app-london) (667)
- [Consulting firms in London](https://www.tamtam.ai/l/consulting-firms-london) (648)
- [IT services companies in London](https://www.tamtam.ai/l/it-services-companies-london) (607)
- [Subscription businesses in London](https://www.tamtam.ai/l/subscription-businesses-london) (544)
- [Venture capital and private equity firms in London](https://www.tamtam.ai/l/vc-and-private-equity-firms-london) (539)
- [Marketing and communications agencies in London](https://www.tamtam.ai/l/marketing-agencies-london) (533)
- [Retail Apparel and Fashion companies in London](https://www.tamtam.ai/l/retail-apparel-and-fashion-companies-london) (498)
- [Advertising Services companies in London](https://www.tamtam.ai/l/advertising-services-companies-london) (480)
- [Companies with in-house R&D in London](https://www.tamtam.ai/l/r-and-d-companies-london) (477)
- [AI companies in London](https://www.tamtam.ai/l/ai-companies-london) (456)
- [Investment Management companies in London](https://www.tamtam.ai/l/investment-management-companies-london) (452)
- [Hotel and hospitality groups in London](https://www.tamtam.ai/l/hospitality-groups-london) (445)
- [Luxury brands in London](https://www.tamtam.ai/l/luxury-brands-london) (428)
- [AI-native companies in London](https://www.tamtam.ai/l/ai-native-companies-london) (407)
- [E-commerce companies in London](https://www.tamtam.ai/l/ecommerce-companies-london) (384)

## The same list elsewhere in United Kingdom

- [Corporate groups and holding companies in the United Kingdom](https://www.tamtam.ai/l/holding-companies-united-kingdom) (666)
- [Corporate groups and holding companies in England](https://www.tamtam.ai/l/holding-companies-england) (578)
- [Corporate groups and holding companies in Scotland](https://www.tamtam.ai/l/holding-companies-scotland) (39)

## The same list elsewhere

- [Corporate groups and holding companies in the world](https://www.tamtam.ai/l/holding-companies-in-the-world) (12,864)
- [Corporate groups and holding companies in Europe](https://www.tamtam.ai/l/holding-companies-in-europe) (4,396)

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Source: https://www.tamtam.ai/l/holding-companies-london