RSM, the 6th largest global network in audit, accounting, and consulting, conducted the financial, tax, social, and IT buy-side due diligences for CELNOR Group, an international group founded by Simon Parrington with the support of Inflexion Capital, specializing in Testing, Inspection, Certification, and Compliance (TICC) services, during the acquisition of the chemical analysis laboratories TERA Environnement and Toxilabo from the TERA Group, a major player in real-time air quality measurement and valorization, listed on Euronext Growth.

CELNOR Group was supported by a Franco-British RSM team, supervised by Mark Leyland, Eric Fougedoire, Laura Bollen, and Cécile Guyot, RSM partners. 

This transaction highlights the expertise of the Corporate Finance division in supporting leading TICC sector players in their strategic international growth projects.

Official Press Release from TERA Group

TERA Group, a major player in real-time air quality measurement and valorization, announces the 100% sale of the TERA Environnement and Toxilabo laboratories, assets of its “laboratory chemical analysis” business line, to CELNOR France.

The sale of this historic Air Quality analysis activity concerns the laboratories in Crolles and Fuveau for TERA Environnement, as well as the Nantes laboratory for TOXILABO. CELNOR France, a subsidiary of the British CELNOR Group, which currently has over 1,600 employees, is making its first acquisition in France with the ambition to become a major international player in the testing, inspection, certification, and compliance sector.

A significant strategic shift

This sale is part of TERA Group’s transformation strategy initiated since its July 2019 IPO. It marks the Group’s refocusing on its real-time measurement activities (driven by TERA Sensor, Omwave, and Atmotrack), which will take over the laboratory analysis activity to drive the Group’s growth.

This evolution aims to accelerate TERA Group’s medium- and long-term growth by focusing on high-potential markets¹ where few players combine laboratory pollutant measurement expertise (gained in the past) with the specific constraints related to air quality (humidity, interferences, etc.) to offer high-performance products and solutions. By concentrating on real-time measurement, TERA Group strengthens the visibility of its offering and continues its international expansion.

Short-term impact

In the short term, this sale will have a significant impact on the Group’s revenue and profitability. In 2024, the laboratory activity represented 84% of revenue, with an EBITDA exceeding 20%, compared to a consolidated EBITDA of 7% for the entire Group.
The number of employees will decrease from nearly 110 to around thirty.

A strengthened financial structure

This transaction allows TERA Group to strengthen its financial structure while repaying almost all of its debt. It will also accelerate the ongoing industrialization of several new products and enable the launch of new developments.

Furthermore, as announced in its press release of July 18, 2025², TERA Group will use part of the proceeds from the sale to launch a public share buyback offer (OPRA) on its own shares. This initiative is expected to involve €13 million at a purchase price of €6.5 per TERA Group share. The historical shareholders plan to participate in this OPRA, which also provides a liquidity opportunity for other TERA Group shareholders.

The terms and conditions of the OPRA will be subject, among other things, to the opinion of an independent expert and the approval of TERA Group shareholders at an extraordinary general meeting. The OPRA project, expected to be filed during Q4 2025, will be subject to review by the Autorité des Marchés Financiers.

Pascal Kaluzny, Founder and CEO of TERA Group, states: “TERA Group continues to follow its roadmap. The planned sale of our TERA Environnement and Toxilabo laboratories allows us to focus on our real-time air quality measurement activities. The proceeds from the sale enable us to accelerate ongoing developments and offer liquidity to all our investors on part or all of their holdings.”

The RSM team:

• Financial due diligence : Mark Leyland, Eric Fougedoire, Laura Bollen, Marine Berge, Bilinda Nassif
• Tax and social due diligences  : Cécile Guyot, Déborah Kocher, Aurélie Rouquier
• IT due diligence: Jocelyn Grignon