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Sullivan Street Partners
Sullivan Street Partners launched in 2011 after its founding team spent years executing complex turnarounds and corporate carve-outs.
Sullivan Street Partners
Sullivan Street Partners launched in 2011 after its founding team spent years executing complex turnarounds and corporate carve-outs. Tamberlin and Sanders, both former GE Capital and Close Brothers executives, structured the firm to apply large-company restructuring rigor to the UK lower mid-market, where fragmented ownership and under-invested management teams consistently produce assets that larger private equity funds overlook. The partnership model is deliberately compact, designed around principals leading transactions rather than delegating to junior teams. The firm pursues control buyouts, corporate spin-offs, and distressed-for-control situations. Its investment approach spans operational turnarounds in UK industrials, healthcare services, and consumer-facing businesses. Confirmed past portfolio companies include Two Counties Vets, a veterinary services group, and Bioganix, an organic waste treatment operator (per Real Deals, 2018). Deal structures typically involve significant equity co-investment from the principals alongside institutional limited partners, with a preference for situations where management teams benefit from fresh strategic direction. Geographic concentration remains nearly exclusively within the United Kingdom. Headquartered in London, the firm operates with a lean team. August 2022 saw Sullivan Street exit Bioganix, a specialist composting business, to private equity house Ancala Partners — a realization that underscored its thesis of building operational value in overlooked infrastructure-adjacent businesses (per Real Deals, August 2022). The firm has also been linked to discussions around acquiring veterinary assets through Two Counties Vets, folding clinical practice management into a specialized buy-and-build platform play. Its investor base includes European institutional limited partners. The firm's structural distinction lies in its rehabilitation DNA. Rather than competing on multiple expansion or financial engineering, Sullivan Street enters situations where operational distress, succession gaps, or corporate neglect have suppressed performance — a posture closer to special situations than classic mid-market buyout. It often acquires businesses with genuine recovery risk that sponsors with standardized return models cannot underwrite, creating a sourcing advantage in proprietary, off-auction processes.
General information
Firm type
Private Equity
Year founded
2011
AUM
Undisclosed
Location
Region
Europe
Country
United Kingdom
City
London
Corporate office
London, United Kingdom
Principals
Layton Tamberlin
Managing Partner
Richard Sanders
Managing Partner
Sector focus
Frequently asked questions
What does Sullivan Street Partners actually do?
It is a London-based private equity firm that acquires controlling stakes in UK lower mid-market companies, typically with enterprise values between £10 million and £100 million. The firm specializes in situations requiring substantial operational improvement — corporate carve-outs, succession-driven sales, and distressed or underperforming assets. Its principals are directly involved in post-acquisition transformation, reflecting a hands-on, restructuring-informed investment style.
Who makes investment decisions at Sullivan Street?
Managing Partners Layton Tamberlin and Richard Sanders lead all investment decisions. Both spent formative years in structured finance and restructuring roles at GE Capital and Close Brothers before founding the firm in 2011. The partnership is deliberately compact, with deal execution led by the senior principals rather than a large multi-tiered investment committee.
Does Sullivan Street focus on any particular sectors?
The firm is generalist within the UK lower mid-market but its most publicly documented investments cluster around healthcare services (notably veterinary platforms), industrial services, and environmental infrastructure. Previously held assets include Bioganix, an organic waste processing business, and Two Counties Vets, a veterinary group. The firm avoids sectors dominated by rapid technological obsolescence, favoring businesses with tangible operational levers.
How does Sullivan Street source deals?
The firm relies heavily on proprietary sourcing through its principals' long-standing UK corporate networks and restructuring advisory relationships. Because it pursues off-market, complex situations — distressed carve-outs, family succession disposals, and underperforming corporate divisions — it often sees transactions that never reach broad auction processes. Large banks and accountancy practices in the UK mid-market restructuring community are a key origination channel.
How is Sullivan Street different from a standard UK mid-market buyout fund?
Standard buyout funds in the UK mid-market generally acquire stable, cash-generative businesses and apply leverage and multiple-arbitrage to generate returns. Sullivan Street specifically targets businesses requiring deep operational rehabilitation — under-managed, distressed, or orphaned assets where standard sponsors see too much execution risk. The firm's principals directly run transformation programs post-close, functioning more like turnaround operators than conventional financial sponsors.
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