nexfibre is buying Netomnia's owner. Will the UK regulator see harm to competition?

What happened

The CMA publishes the merging parties’ joint response to its areas of focus document, the latest filing in the Phase 2 inquiry into nexfibre’s acquisition of Substantial.

nexfibre, owned jointly by Liberty Global, Telefónica and InfraVia, is buying Substantial, the company that owns the Netomnia, brsk and YouFibre broadband networks. The Competition and Markets Authority (CMA), the UK competition regulator, opened its review on 29 June 2026. On 1 July, at the firms’ own request, it sent the deal straight to a full, in-depth review, called Phase 2, under its fast-track route.

A panel of four chaired by Cyrus Mehta runs the review. On 17 July the CMA accepted temporary promises from Substantial, known as interim undertakings, and published them on 24 July.

Rivals have had their say. The CMA set out the issues it would look at on 7 July, with replies due by 20 July. BT Group, Grain Connect and Hyperoptic sent views on 24 July, Sky on 3 August and CityFibre on 5 August. The CMA published the two firms’ joint reply on 14 August.

The business question is whether joining two of the bigger challengers to Openreach removes competition in the places where both networks are built.

An interim report is due in early October. The CMA’s timetable of 7 July has the panel gathering evidence until then. If needed, it consults on fixes from mid to late October, holds hearings with the firms in late October and early November, and publishes a final report in early December. The legal deadline is 15 December.

The panel decides alone under the Enterprise Act 2002. Ministers cannot step in on competition grounds.

Sources: CMA, CMA administrative timetable

The Pattern

Five telecoms mergers reached this stage with findings on record. We set the rule before counting: every telecoms merger the CMA sent to a Phase 2 review whose first findings, now called an interim report, are published on its case page. We asked one thing: did those findings say the deal would substantially reduce competition? Three older cases have only final results on record, so they are left out.

The Read

History leans slightly towards clearance. Three of the five earlier telecoms reviews found no problem at the interim stage, and the two that did ended with fixes, not a ban. Both of those involved mobile networks or phone masts across the whole country. A fibre case like this one turns on local overlap. If the panel finds enough competition from Openreach and CityFibre where the two networks meet, the interim report clears the deal. The record is also small, five cases.

This deal has signs that point the other way. The firms asked to skip the first stage of review, which buyers tend to do when they expect to agree fixes rather than argue for a clean result. The temporary promises keep the businesses separable, which a later sale of part of them would need. The rivals objecting are BT, Sky, CityFibre and Hyperoptic, all big players. And both firms build fixed networks in the same areas, where harm to competition is easiest to explain, unlike the two deals joining fixed and mobile networks that the CMA cleared in 2016 and 2021.

The timing is a useful sign. If the panel publishes its interim report in early October, it has found the case simple, in either direction. A delay into late October would fit a panel drafting fixes.