---
title: "ALCOR UNDERWRITING LONDON LIMITED — Ownership Dossier"
canonical: https://whiteintel.dev/entity/f021e03f-2ec2-5557-a943-fbdfc03ed2aa
json: https://whiteintel.dev/api/public/dossier/f021e03f-2ec2-5557-a943-fbdfc03ed2aa
identifier: oo:GB-COH-12663118
jurisdiction: GB
risk: Low
source: WhiteIntel corporate-ownership graph
---

# ALCOR UNDERWRITING LONDON LIMITED

**Type:** Company  
**Jurisdiction:** GB  
**Identifier:** `oo:GB-COH-12663118`  
**Risk level:** Low  
**Canonical dossier:** https://whiteintel.dev/entity/f021e03f-2ec2-5557-a943-fbdfc03ed2aa  
**Structured JSON / MCP:** https://whiteintel.dev/api/public/dossier/f021e03f-2ec2-5557-a943-fbdfc03ed2aa  

## Ownership & control

### Owners / controllers

- **ALCOR UK HOLDINGS LIMITED** (beneficial owner) — 100% — https://whiteintel.dev/entity/96a3a953-fdfd-56e2-8b9d-8bfe438dc453
- **ALCOR UK HOLDINGS LIMITED** (beneficial owner) — 87.5% — https://whiteintel.dev/entity/96a3a953-fdfd-56e2-8b9d-8bfe438dc453

### UBO chain (walk to the ultimate owner)

1. **ALCOR UK HOLDINGS LIMITED** — beneficial owner 100% → *ALCOR UNDERWRITING LONDON LIMITED*
1. **ALCOR UK HOLDINGS LIMITED** — beneficial owner 87.5% → *ALCOR UNDERWRITING LONDON LIMITED*
2. **OCTAVE SPECIALTY LIMITED** — beneficial owner 62.5% → *ALCOR UK HOLDINGS LIMITED*
3. **NEON HOLDINGS (U.K.) LIMITED** — beneficial owner 37.5% → *OCTAVE SPECIALTY LIMITED*
3. **Mr John Paul Cavanagh** — beneficial owner 37.5% → *OCTAVE SPECIALTY LIMITED*
3. **Mr Andrew James Tom Milligan** — beneficial owner 37.5% → *OCTAVE SPECIALTY LIMITED*
3. **Paraline Group Ltd** — beneficial owner 37.5% → *OCTAVE SPECIALTY LIMITED*
3. **Mr Andrew James Tom Milligan** — beneficial owner 37.5% → *OCTAVE SPECIALTY LIMITED*
3. **Mr John Paul Cavanagh** — beneficial owner 37.5% → *OCTAVE SPECIALTY LIMITED*
3. **Octave Specialty Group, Inc.** — beneficial owner 62.5% → *OCTAVE SPECIALTY LIMITED*
4. **Gai Holding Bermuda Ltd** — beneficial owner 100% → *NEON HOLDINGS (U.K.) LIMITED*
4. **Neon Capital Limited** — beneficial owner 87.5% → *NEON HOLDINGS (U.K.) LIMITED*
5. **RIVERSTONE HOLDINGS LIMITED** — beneficial owner 87.5% → *Gai Holding Bermuda Ltd*
5. **Gai Holding Bermuda Ltd** — beneficial owner 87.5% → *Gai Holding Bermuda Ltd*
6. **RIVERSTONE INTERNATIONAL HOLDINGS LIMITED** — ultimate parent → *RIVERSTONE HOLDINGS LIMITED*
6. **RIVERSTONE INTERNATIONAL HOLDINGS LIMITED** — parent → *RIVERSTONE HOLDINGS LIMITED*

## Company profile (live · UK Companies House)

- **Company number:** `12663118`
- **Status:** active
- **Type:** ltd
- **Incorporated:** 2020-06-11
- **Registered office:** The Hallmark Building, 2nd Floor, 52-56 Leadenhall Street, London, EC3A 2BJ, England
- **SIC:** 66220

### Officers

- CHABE, Tamara — secretary · appointed 2025-07-30
- MARSDEN, Heather Elizabeth — secretary · appointed 2020-11-26
- NAHER, Shamsun — secretary · appointed 2023-02-21
- CAVANAGH, John Paul — director · British · appointed 2020-09-30
- GRAHAM, Joshua James — director · British · appointed 2020-09-07
- MARSDEN, Heather Elizabeth, Mrs. — director · American · appointed 2020-06-11
- RAYNER, Paul Michael — director · British · appointed 2020-06-11
- BAKER, Katie Victoria, Ms. — secretary · appointed 2020-06-11 · resigned 2025-08-04
- RUGHANI, Shradha, Mrs. — secretary · appointed 2020-06-11 · resigned 2023-01-26

### Beneficial owners (Persons with Significant Control)

- [Alcor Uk Holdings Limited](https://whiteintel.dev/entity/96a3a953-fdfd-56e2-8b9d-8bfe438dc453) — 75–100% shares · corporate PSC · England — since 2020-06-11

## Provenance

- companies_house_bulk — https://find-and-update.company-information.service.gov.uk/company/12663118
- OpenOwnership — https://find-and-update.company-information.service.gov.uk/company/12663118

---

_This is the markdown-for-agents view of the WhiteIntel dossier for **ALCOR UNDERWRITING LONDON LIMITED**. Human view: https://whiteintel.dev/entity/f021e03f-2ec2-5557-a943-fbdfc03ed2aa · Structured JSON: https://whiteintel.dev/api/public/dossier/f021e03f-2ec2-5557-a943-fbdfc03ed2aa._

_Risk levels are heuristic investigative leads, not legal determinations of beneficial ownership. Every claim carries a source; an absent edge means "not yet observed in current sources", not "does not exist"._