Nexfibre’s proposed £2 billion acquisition of Substantial Group, the owner of Netomnia, Brsk, YouFibre and Brsk ISP, has run into a potentially decisive regulatory obstacle after Britain’s Competition and Markets Authority (CMA) provisionally concluded that the transaction could substantially reduce competition in the wholesale supply of fixed broadband services.
The finding is particularly striking because the regulator’s concern does not rest simply on the disappearance of one alternative fibre operator. The Competition and Markets Authority has provisionally concluded that, without nexfibre’s transaction, rival CityFibre would most likely have acquired Substantial instead, creating what the regulator considers a stronger independent competitor to both BT Group’s Openreach network and the wider Virgin Media O2/nexfibre platform.
That turns the review into something more consequential than a routine telecom merger investigation. Britain’s alternative fibre sector has spent billions of pounds constructing overlapping full-fibre networks, yet many operators remain heavily indebted and struggle to convert network coverage into enough paying customers. Consolidation increasingly appears economically necessary, but the Competition and Markets Authority is effectively asking whether the identity of the consolidator can determine whether competition becomes stronger or weaker.
Nexfibre strongly disagrees. The fibre joint venture backed by Liberty Global Ltd., Telefónica, S.A. and InfraVia Capital Partners argues that the acquisition would create the scale and investment required to challenge Openreach rather than undermine competition. The two sides are therefore debating the same structural problem from opposite directions: whether Britain gets a stronger broadband market by allowing nexfibre to become a much larger national network, or by preserving a separate CityFibre-led challenger.
What exactly is nexfibre buying for £2 billion?
Nexfibre agreed in February to acquire 100% of Substantial Topco Limited, the parent of Netomnia and the associated Brsk and YouFibre businesses, for an enterprise value of £2 billion.
Substantial was expected to have more than 3.4 million fibre premises and more than 500,000 customers by completion. Netomnia had grown rapidly since its creation in 2019 and had become the United Kingdom’s second-largest alternative full-fibre network operator, behind CityFibre among the independent fibre challengers commonly known as altnets.
The transaction is more complicated than a straightforward network acquisition. Nexfibre plans to retain the fibre infrastructure, while Virgin Media O2 would acquire Substantial’s retail operations, including YouFibre and Brsk, for £150 million.
Virgin Media O2 would also move substantial traffic onto the enlarged nexfibre network. The February transaction structure said Virgin Media O2 would pay wholesale fibre-access fees for customers in approximately 2.5 million premises where its existing network overlaps Netomnia and for another 2.1 million Virgin Media O2 hybrid fibre-coaxial premises that nexfibre intends to upgrade to fibre.
In exchange for the wholesale traffic commitment covering those approximately 4.6 million premises, Virgin Media O2 would receive about £1.1 billion in cash and an indirect 15% interest in nexfibre. The structure was designed not merely to buy Netomnia but to accelerate a broader reorganisation of fibre infrastructure around nexfibre and Virgin Media O2.
Why does nexfibre say the acquisition would create a stronger Openreach challenger?
The strategic argument is scale.
Nexfibre said the combination of its existing network, Netomnia’s infrastructure and fibre upgrades to adjacent Virgin Media O2 premises would create a footprint of roughly 8 million premises by the end of 2027. That would leave it far smaller than Openreach nationally but large enough to represent one of the most substantial alternative wholesale fibre platforms in Britain.
Openreach says it is on course to reach 25 million homes and businesses with full fibre by the end of 2026 and could eventually reach as many as 30 million premises by the end of the decade if investment conditions remain supportive.
Against that scale, nexfibre argues that fragmentation works in Openreach’s favour. Smaller fibre builders often duplicate fixed costs, negotiate separately with lenders and suppliers and struggle to attract enough wholesale customers to fill networks that are expensive to construct but relatively cheap to operate once utilisation becomes high.
Nexfibre has said the Substantial transaction would unlock £3.5 billion of international investment and create a scaled, financially sustainable alternative to Openreach. Chief Executive Officer Rajiv Datta has argued that delays in consolidation reinforce the incumbent’s position rather than protect meaningful long-term competition.
That argument has intuitive economic appeal. A fibre network that passes millions of homes but attracts too few customers can destroy capital even if the underlying infrastructure is technically excellent.
The Competition and Markets Authority, however, is asking a different question: whether nexfibre needs Netomnia specifically to reach sufficient scale, or whether Britain would benefit more if the Netomnia network strengthened a different competitor.
Why does the CMA think CityFibre is the important alternative buyer?
The regulator’s provisional counterfactual is the most unusual part of the case.
The Competition and Markets Authority believes that if nexfibre had not agreed to acquire Substantial, CityFibre would most likely have bought the business. CityFibre had participated in the earlier sale process, and the regulator is therefore comparing the proposed transaction not with a world in which Netomnia simply remains independent forever, but with one in which CityFibre becomes the owner.
That matters because CityFibre is structurally separate from both Openreach and Virgin Media O2/nexfibre.
If CityFibre acquired Netomnia, the regulator believes the enlarged CityFibre network could provide stronger wholesale competition against two major infrastructure groupings: Openreach on one side and the Virgin Media O2/nexfibre platform on the other.
Under the proposed nexfibre transaction, by contrast, Netomnia’s physical network would move into a platform whose owners Liberty Global and Telefónica also jointly own Virgin Media O2. Virgin Media O2 would then acquire the retail businesses and commit large volumes of wholesale traffic to nexfibre.
The regulator has provisionally concluded that this structure could weaken competition in wholesale fixed broadband services relative to the CityFibre alternative.
CityFibre has unsurprisingly supported that analysis and has urged the Competition and Markets Authority to stop the current deal. Nexfibre has rejected the counterfactual as unrealistic, with Datta describing the regulator’s alternative scenario as a “counter-fantasy.”
Why does network overlap matter so much to the competition case?
Fixed broadband competition is unusually local.
Two network operators may both cover millions of premises nationally while competing directly against one another in only part of their footprints. What matters to a household or retail broadband provider is how many usable wholesale networks actually reach a particular address.
CityFibre has previously argued that roughly 80% of the Netomnia network overlaps with Virgin Media O2’s footprint. The precise competitive effects depend on the local market definition and the regulator’s analysis, but extensive overlap creates the possibility that infrastructure currently competing against Virgin Media O2 could ultimately become part of a closely connected wholesale platform.
The Competition and Markets Authority’s concern appears particularly important in parts of northern England and the Midlands where the alternative network choices differ from the national picture.
That is why simple national fibre-coverage figures can be misleading. Britain can have multiple large networks in aggregate while some local areas still depend heavily on only two or three practical wholesale alternatives.
The regulator’s provisional position suggests it believes a CityFibre-Netomnia combination would preserve more independent infrastructure competition in relevant overlapping areas than a nexfibre-Netomnia combination.
Why is the UK fibre market consolidating in the first place?
The uncomfortable answer is that the economics of the altnet boom have become increasingly difficult.
Britain experienced an extraordinary investment cycle as private capital funded dozens of alternative fibre builders seeking to challenge Openreach and Virgin Media O2. More than £31 billion has been invested in the wider sector over roughly a decade, according to industry analysis reported by the Financial Times.
The infrastructure build worked from a coverage perspective. Ofcom reported that full fibre was available to 24.9 million UK homes, or 82% of residential premises, by January 2026, compared with less than a quarter of homes only five years earlier.
Commercial returns have been much harder to achieve.
Enders Analysis estimated that major UK altnets collectively generated approximately £1.5 billion of accounting losses in 2024 while carrying around £9 billion of debt. Consumer take-up on individual alternative networks has often remained far below the level originally assumed in business plans, leaving expensive fibre assets with insufficient revenue to cover operating and financing costs.
Higher interest rates have made the problem worse because many networks were built during an era when infrastructure capital was significantly cheaper.
That is why consolidation is not simply an opportunistic corporate strategy. For portions of the altnet industry, it may be necessary to combine networks, eliminate duplicated overhead and concentrate customers onto fewer infrastructure platforms.
The Competition and Markets Authority therefore faces a difficult trade-off. Blocking consolidation can preserve nominal competition, but preventing financially necessary combinations could eventually leave weaker operators unable to invest or refinance.
Could the CMA block a deal that promises billions of pounds of new investment?
Yes, if the regulator ultimately concludes that the competitive harm outweighs the claimed benefits.
Nexfibre says the transaction would unlock approximately £3.5 billion of investment and allow it to upgrade 2.1 million Virgin Media O2 premises adjacent to the Netomnia network. The majority of those upgrades were originally expected to be ready by the end of 2027.
The Competition and Markets Authority is not required simply to accept those benefits at face value. It must assess whether they are merger-specific, sufficiently likely and large enough to offset any reduction in competition.
The regulator’s provisional conclusion suggests it is not yet persuaded that nexfibre’s investment argument overcomes the competition concerns.
This is especially important because Virgin Media O2 and nexfibre already have incentives and capabilities to expand their fibre network independently. If the regulator believes substantial portions of the promised investment would occur even without buying Netomnia, the merger-specific benefit becomes smaller.
Nexfibre disputes that logic and argues that market conditions require greater scale and certainty to support continued investment.
The disagreement therefore comes down partly to what Britain’s fibre market would realistically look like without this transaction, not merely what the combined company says it plans to build after completion.
Why does the regulatory dispute matter for broadband prices and wholesale choice?
Wholesale competition eventually influences retail competition.
Broadband providers such as Sky, Vodafone and other retail operators can purchase access to infrastructure rather than building nationwide networks themselves. More viable wholesale networks can increase bargaining options and reduce dependence on Openreach.
Ofcom has explicitly structured its 2026-2031 telecom regulation around encouraging infrastructure competition while preventing Openreach from using its scale to foreclose rivals. In September, Ofcom even required Openreach to withdraw one proposed commercial customer-acquisition offer after concluding it raised competition concerns under the new regulatory framework.
That broader policy makes the nexfibre case particularly delicate. The UK has spent years encouraging alternative networks to invest so that Openreach faces genuine infrastructure competition, yet the financial weakness of those challengers is now pushing the sector toward consolidation.
Too little consolidation could leave dozens of subscale and financially strained networks. Too much consolidation could recreate a market dominated by only a small number of infrastructure owners.
The Competition and Markets Authority appears to favour a structure in which Openreach, Virgin Media O2/nexfibre and an enlarged CityFibre remain three substantial wholesale infrastructure competitors.
That model may offer more competitive tension than allowing nexfibre to absorb Netomnia while CityFibre remains smaller, but it also assumes CityFibre itself can finance and successfully integrate the business.
Is CityFibre financially positioned to become the alternative consolidator?
CityFibre has been actively positioning itself as a consolidator.
The company secured a £2.26 billion financing package in 2025 that included new equity and additional debt capacity, with part of the facility designed to support acquisitions. It has also completed smaller infrastructure transactions as the UK altnet sector moves into its consolidation phase.
That does not mean a CityFibre purchase of Netomnia is guaranteed if the current deal fails.
The Competition and Markets Authority’s counterfactual is a regulatory assessment of what most likely would have happened without the nexfibre agreement. It is not a binding commitment requiring CityFibre to submit another offer at the same valuation or guaranteeing that Netomnia’s owners would accept one.
Market conditions, financing costs and Netomnia’s operating performance could all change.
The regulator’s preferred competitive structure therefore still carries execution uncertainty. If the nexfibre deal is blocked and no viable alternative acquisition follows, the eventual market outcome could differ from the scenario currently underpinning the provisional competition analysis.
That is likely to be one of the strongest points nexfibre raises during the remedies and consultation phase.
What does the £2 billion valuation say about fibre consolidation economics?
The acquisition values Substantial at £2 billion on an enterprise-value basis.
That figure covers a business expected to have more than 3.4 million fibre premises and over 500,000 customers by completion, but simple per-premises calculations can be misleading because the transaction includes operating businesses, customer relationships, debt and infrastructure at different stages of maturity.
What matters is whether a larger network owner can generate higher returns from those assets than Substantial could independently.
The strategic logic depends heavily on customer penetration. Fibre networks have high upfront construction costs, but the marginal cost of adding additional users to an existing network can be far lower than building the network itself.
A buyer that can place a large existing retail customer base onto Netomnia infrastructure therefore has an immediate advantage. Virgin Media O2’s planned wholesale traffic commitment is central to the nexfibre economics because it would push substantial volumes onto the acquired network without waiting years to win those customers one household at a time.
That same feature is exactly what creates regulatory concern. Commercially, guaranteed traffic can improve asset economics. Competitively, linking a major retail provider so closely with one wholesale infrastructure platform can reduce the independence of networks that previously competed.
How are investors treating the regulatory setback?
The immediate public-market reaction was relatively muted compared with the strategic importance of the ruling.
Liberty Global Class A shares closed at $8.92 on October 2, unchanged from the previous session, although they had fallen from $9.13 two sessions earlier. Market data also showed Telefónica shares modestly higher on the day.
Those movements should not be interpreted as a clean referendum on the Netomnia review. Both companies have large international portfolios, and nexfibre represents only one component of their broader operations.
Liberty Global’s longer-term share performance has been considerably weaker, with the Class A stock down roughly 24% over the preceding year by October 2. That broader decline reflects multiple issues across Liberty Global’s portfolio and cannot be attributed specifically to the UK fibre transaction.
For investors, the more important financial question is whether the deal ultimately delivers the expected network scale and cash proceeds associated with Virgin Media O2’s participation or whether a regulatory block forces the shareholders to rethink their UK fibre strategy.
What remedies could save the nexfibre-Netomnia transaction?
The Competition and Markets Authority has given the parties an opportunity to propose remedies.
A completed Phase 2 remedies submission is due by October 16, while responses to the interim findings are due by October 23. The statutory deadline for the final decision is December 15.
The challenge is that remedies must address the actual source of the regulator’s concern.
If the Competition and Markets Authority believes the fundamental harm comes from moving Netomnia into the Virgin Media O2/nexfibre orbit instead of allowing CityFibre to acquire it, a narrow behavioural commitment on pricing may not be enough. Structural remedies can be more difficult because the principal asset being acquired is the fibre network itself.
Potential solutions could theoretically involve wholesale-access commitments, governance protections, restrictions around Virgin Media O2 traffic or disposals in overlapping areas, but no final remedy package has been announced and it would be premature to predict which measures the regulator would consider sufficient.
The more extensive the required remedy, the greater the risk that the original commercial logic deteriorates.
That is why the next two months matter. Nexfibre must decide whether there is a workable path to approval or whether the conditions required to satisfy the regulator would undermine the transaction it originally agreed.
What does this case mean for the wider UK broadband shakeout?
The consequences extend beyond Netomnia.
Britain’s altnet sector needs consolidation, but this investigation shows that regulators will not necessarily treat every consolidation as equally beneficial.
A combination that creates larger networks can improve financial sustainability while simultaneously reducing local infrastructure choice. Future transactions will therefore be judged not merely on whether the acquired operator needs scale, but on which buyer creates the strongest competitive market afterward.
That could effectively influence who becomes Britain’s long-term fibre consolidators.
If nexfibre succeeds, the United Kingdom may move toward three large infrastructure groupings dominated by Openreach, Virgin Media O2/nexfibre and CityFibre, with a smaller tail of regional networks. If the Competition and Markets Authority blocks the deal and CityFibre ultimately acquires Netomnia, the same broad three-network structure could still emerge, but with a much larger independent CityFibre challenger.
The difference may sound technical, but it goes to the heart of British broadband policy.
The country has largely succeeded in solving the problem of insufficient fibre construction. Ofcom says 82% of homes already had full-fibre access at the start of 2026 and coverage could reach 92% by the end of 2028 if planned deployments are completed.
The next challenge is economic sustainability.
The nexfibre-Netomnia dispute therefore asks a question that regulators across infrastructure markets will increasingly face: when an investment boom produces too many financially weak competitors, how much consolidation can be allowed before the cure begins to undermine the competition the investment was supposed to create?
Discover more from Business-News-Today.com
Subscribe to get the latest posts sent to your email.
