Castellum Aktiebolag
Castellum Aktiebolag (org. no. 556475-5550) is a Swedish limited company (aktiebolag) registered with the Swedish Companies Registration Office (Bolagsverket) on 27 October 1993, with its registered office in Göteborg. The company’s registry status is listed as Active.
Castellum is a commercial property company operating primarily in Sweden, with additional operations in Denmark and Finland. The company acquires, owns, manages and develops real estate on a long-term basis, with a focus on office and logistics space alongside retail and public-sector properties. Its portfolio spans roughly twenty Swedish cities as well as Copenhagen and Helsinki, and the company also holds an approximate one-third interest in Norway’s Entra ASA through an associated-company arrangement.
Castellum’s shares have been listed on Nasdaq Stockholm Large Cap under the ticker CAST since 1997. According to the Castellum Year-end Report 2025, the Castellum group reported consolidated total income of SEK 9,593 million for the 2025 financial year, a year-end property portfolio value of approximately SEK 136.9 billion, and net debt of SEK 56,899 million as of 31 December 2025. These figures are reported at the consolidated group level rather than for the standalone legal entity.
Castellum has been recognised for sustainability performance: it is included in the Dow Jones Sustainability Indices (DJSI) as the only Nordic property company on the index, and its financing framework carries a Green Equity Designation.
In a recent transaction announced in June 2026, Castellum agreed to divest two Stockholm office properties to Alecta Fastigheter for approximately SEK 5.0 billion, part of the company’s ongoing transactions activity alongside its property management and project development operations.
The registry’s Active status reflects Castellum Aktiebolag’s current registration; it does not by itself confirm the scope or level of the company’s trading activity.
- Company fundamentals
- Corporate linkage & group structures
- Digitized company financials
- Firmographics — websites, social profiles, revenue and employee estimates
Shareholders
5
Shareholders of Castellum Aktiebolag
Public disclosure of Castellum Aktiebolag’s shareholders is limited to major, reportable holdings under Nasdaq Stockholm’s disclosure rules rather than a complete shareholder register. Based on shareholder flagging notifications and market data retrieved in September 2026, the largest disclosed shareholder is Akelius Apartments AB, an entity associated with Roger Akelius, reported to hold approximately 25.07% of the capital and votes following a share purchase from M2 Asset Management completed in mid-2026. Rutger Arnhult, previously Castellum’s largest single owner through a holding company, was reported to hold approximately 6.1% of the capital and votes following that transaction, making him the second-largest disclosed shareholder. BlackRock Inc. was reported to hold approximately 5.00% of the shares, and Alecta Tjänstepension Ömsesidigt was reported to hold approximately 1.97% (9,400,000 shares). Historical Castellum corporate governance reports also record Handelsbanken Fonder among the company’s largest registered owners in earlier reporting periods. Percentages above were identified from different reporting dates during this research and may not all represent a single reporting date.
Ultimate beneficial ownership
No ultimate beneficial owner can be reliably confirmed from the sources reviewed. Akelius Apartments AB is the largest disclosed direct shareholder, but the ownership chain connecting it to a natural-person beneficial owner was not confirmed by a primary source during this research, so no UBO percentage is calculated here.
Data availability
Shareholder disclosure for this Nasdaq Stockholm-listed company is categorised as major shareholders only: holdings above statutory flagging thresholds are publicly disclosed, but the complete shareholder base, including smaller holdings, is not.
Sources
- MarketScreener, Castellum AB shareholders, board members, managers and company profile, https://www.marketscreener.com/quote/stock/CASTELLUM-AB-6491340/company/, retrieved 2026-09-18
- MarketScreener news coverage of the Akelius-M2 Asset Management Castellum share transaction, https://www.marketscreener.com/quote/stock/CASTELLUM-AB-6491340/news/, retrieved 2026-09-18
- Castellum, Corporate governance reports (historical), https://www.castellum.com/investors/corporate-governance/, retrieved 2026-09-18
Registry feed — rows exactly as filed with Swedish Companies Registration Office (Bolagsverket), including entries the profile above does not cover.
| Shareholder | Type | Holding | Source Document |
|---|---|---|---|
| VANGUARD TAX-MANAGED FUNDS-Vanguard Developed Markets Index Fund | 9.3% | Swedish Companies Registration Office (Bolagsverket) | |
| VANGUARD Intl Eqy. INDEX Fd.S-Vanguard Global ex-U.S. Real Estate Inde | 4% | Swedish Companies Registration Office (Bolagsverket) | |
| CBRE Global Real Estate Income Fund | 2.9% | Swedish Companies Registration Office (Bolagsverket) | |
| VANGUARD Intl Eqy. INDEX Fd.S-Vanguard FTSE All-World ex-US Index Fd. | 2.2% | Swedish Companies Registration Office (Bolagsverket) | |
| SPDR INDEX SHARES FUNDS-SPDR Portfolio Developed World ex-US ETF | 1.4% | Swedish Companies Registration Office (Bolagsverket) |
Officers
51
Directors and officers of Castellum Aktiebolag
Castellum Aktiebolag’s underlying registry record includes an extensive history of appointments and resignations spanning the period since incorporation in 1993, the great majority of which are historical or resigned entries. Current board composition and executive leadership, as verified on Castellum’s own investor relations pages in September 2026, comprise a seven-member board chaired by Ralf Spann (Chair since 2025), with directors Anna-Karin Celsing, Henrik Käll, Marita Loft, Leif Norburg, Knut Rost and Stefan Wallander. Pål Ahlsén serves as Chief Executive Officer and Group Chief, a role he has held since 2025. Nationality and country of residence are not disclosed for board members or the CEO on the company’s official governance pages reviewed for this research.
Recent officer changes
- Ralf Spann appointed Chair of the Board, 2025 (source: Castellum corporate governance page)
- Pål Ahlsén appointed CEO and Group Chief, 2025 (source: Castellum corporate governance page)
- Marita Loft, Leif Norburg, Knut Rost and Stefan Wallander appointed to the Board, 2025 (source: Castellum corporate governance page)
Data availability
Officer information is current only: the company’s own investor relations pages confirm the active board members and CEO, but exact appointment and resignation dates are not separately stated on those pages. The registry snapshot associated with this profile lists a much larger historical officer count that is not reproduced here.
Sources
- Castellum, Board of Directors, https://www.castellum.se/investerare/bolagsstyrning/styrelse/, retrieved 2026-09-18
- Castellum, Group Management, https://www.castellum.se/investerare/bolagsstyrning/koncernledning/, retrieved 2026-09-18
Registry feed — rows exactly as filed with Swedish Companies Registration Office (Bolagsverket), including entries the profile above does not cover.
Group Structure
Group structure of Castellum Aktiebolag
Castellum Aktiebolag is the top entity shown in its own corporate-linkage record, consistent with its position as the Nasdaq Stockholm-listed parent of the Castellum group; no separate parent company is identified in the sources reviewed. The underlying registry data lists a large number of verified direct and indirect subsidiaries, almost entirely Swedish property-holding companies together with a smaller number of Finnish subsidiaries (including Castellum Finland AB and Castellum Oy), reflecting the group’s operations in Sweden and Finland. Ownership percentages for these subsidiaries are not disclosed in the source data reviewed. Separately, Castellum’s own investor communications state that the group holds an approximate one-third interest in Norway’s Entra ASA through an associated-company arrangement; this is best classified as an affiliate relationship rather than a subsidiary, since full ownership and control details were not independently verified in this research.
Data availability
Subsidiary information is partial: entity names, jurisdictions and registration numbers for numerous Swedish and Finnish subsidiaries are available, but ownership and voting percentages are not disclosed in the reviewed source, and no parent company above Castellum Aktiebolag was identified.
Sources
- Zavia.ai corporate-linkage registry data for Castellum Aktiebolag, internal record, retrieved 2026-09-18
- Castellum, About Castellum (Entra ASA associated-company stake), https://www.castellum.com/about-castellum/, retrieved 2026-09-18
Registry feed — rows exactly as filed with Swedish Companies Registration Office (Bolagsverket), including entries the profile above does not cover.
Castellum Aktiebolag
Sweden
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Frequently Asked Questions
What does Castellum Aktiebolag do?
Commercial real estate investment, management and development (offices, logistics, retail and public-sector properties) across Sweden, Denmark and Finland.
Who owns Castellum Aktiebolag?
Largest disclosed shareholder is Akelius Apartments AB (Roger Akelius), approximately 25.07% of capital and votes (flagging notice, mid-2026); other major holders include Rutger Arnhult (approx. 6.1%) and BlackRock Inc. (approx. 5.00%).
Who is Castellum Aktiebolag's UBO (Ultimate Beneficial Owner)?
No fully verified ultimate beneficial owner identified; Akelius Apartments AB is the largest disclosed shareholder but the ownership chain to a natural person was not confirmed by a primary source in this research.
What is Castellum Aktiebolag's company registration number?
Castellum Aktiebolag's registration number is 5564755550, filed with Swedish Companies Registration Office (Bolagsverket) in Sweden. Its current status on the register is active.
Is Castellum Aktiebolag still an active company?
Castellum Aktiebolag's status on Swedish Companies Registration Office (Bolagsverket) is listed as active.
When was Castellum Aktiebolag incorporated?
Castellum Aktiebolag was incorporated on 27 October 1993, according to Swedish Companies Registration Office (Bolagsverket).
What is Castellum Aktiebolag's registered address?
The registered address on file for Castellum Aktiebolag is GÖTEBORG, Sweden.
What legal structure is Castellum Aktiebolag registered as?
Castellum Aktiebolag is registered as a Private limited company (Ltd.) in Sweden.
What is Castellum Aktiebolag's revenue?
SEK 9,593 million total income for FY2025 (Castellum Group, consolidated), per the Castellum Year-end Report 2025.
Is Castellum Aktiebolag listed on a stock exchange?
Listed on Nasdaq Stockholm Large Cap under ticker CAST since 1997.
Who are the officers/directors of Castellum Aktiebolag?
Board chaired by Ralf Spann; CEO and Group Chief is Pål Ahlsén (since 2025), per Castellum's official investor relations pages.
Does Castellum Aktiebolag have a parent company or subsidiaries?
Castellum Aktiebolag is the listed parent of the Castellum group, with numerous verified Swedish and Finnish property-holding subsidiaries and an approximate one-third associate stake in Norway's Entra ASA.
Can Zavia monitor changes to Castellum Aktiebolag's ownership over time?
This profile reflects a point-in-time snapshot from Swedish Companies Registration Office (Bolagsverket). Zavia's monitoring API can track changes to Castellum Aktiebolag's registered shareholders, officers, and group structure going forward, flagging updates as they're filed rather than requiring a manual recheck.
Can I access Castellum Aktiebolag's data through an API?
Yes. Zavia's API connects directly to official government ownership registries across 195 countries and territories, including Sweden, so records like Castellum Aktiebolag's registration, shareholder, UBO, and group-structure data can be queried programmatically instead of viewed one page at a time.
Where does this company information come from, and how current is it?
This record is sourced directly from Swedish Companies Registration Office (Bolagsverket) and was last synced on 18 September 2026.