10. Telent Technology Services

Revenue: £460.7m

Telent Technology Services specialises in designing, building, supporting and managing digital infrastructure across some of the UK’s most critical sectors, including transport, telecoms, public safety and the wider public sector. Its customer base includes organisations such as BT, Network Rail, the Home Office, and multiple fire and ambulance services.

The company operates through three sector-aligned business units — Network Services, Transport, and Telecoms — delivering services such as network installation and maintenance, safety and control systems, and cybersecurity. Its dedicated security arm, Cyro Cyber, plays a growing role in its proposition, particularly to public sector and emergency services clients.

In April 2025, Telent was acquired by infrastructure services group M Group, which aims to combine Telent’s digital and cybersecurity expertise with its own footprint across water, energy, transport and telecoms. The acquisition, which follows M Group’s purchase of energy efficiency firm Aran, is subject to regulatory approval in the UK and Ireland due to Telent’s role in national infrastructure projects.

CEO Jo Gretton said the deal would enable Telent to broaden its offering within its existing sectors, while also opening opportunities in areas such as water through M Group’s established customer relationships. The Telent brand will be retained, with a refreshed identity as Telent, part of M Group.

The deal comes off the back of strong financial results for the year ended 31 March 2024, with Telent reporting EBITDA of £27.8m from operating activities — up from £14m the previous year.