Guillaume Fornier advises companies, whether listed or unlisted, in their strategic acquisitions and disposals, capital transactions, shareholder relations or partnerships. Guillaume also acts on international M&A transactions.
He is the author of several articles on Corporate Law and teaches Corporate Law at the University of Paris-Saclay.
Background
Lawyer since : 2010
Bar. : Paris
Language(s) : French - English - German
Training :
- École de formation du barreau, CAPA – 2009
- ESSEC, Master of Business Administration – 2009
- University Paris 1 Panthéon-Sorbonne, Master 2 Financial Law – 2008
Publications
- Quelques enseignements sur l’applicabilité de la procédure des avantages particuliers aux sociétés par actions simplifiées – Option Droit & Affaires 24/04/2024
- Imprevision and transfer of shares: constitutionality of Article L. 211-40-1 of the CMF – Option finance, 03/07/2023
- In the silence of the statutes, the director of SAS is revocable as nutum…-Option finance, 30/05/2022
- Clause de non-concurrence et contrepartie financière : quelques précisions complémentaires par la chambre commerciale de la Cour de cassation – Option Finance, 15/10/2021
- Le contrôle des investissements étrangers se cherche un avenir européen, Magazine Reflets, novembre 2020
- Un an après la réforme du droit des obligations, Option Finance, février 2017 (avec R. Ducatez)
- Loi Sapin 2 – Vers une adoption d’un dispositif de prévention de la corruption à la charge des sociétés, Option Finance, septembre 2016 (avec Ph. Portier)
- Loi Sapin 2 – L’imminente révolution du dispositif de lutte anticorruption en France ?, Magazine des Affaires, septembre 2016 (avec Ph. Portier)
- La société libre de partenariat : le « Limited Partnership » à la française, Option Finance, octobre 2015 (avec N. Goetz)
- Advises JIN on the acquisition of Atchik
- Advised the founders on the sale of Rhis Solutions to Tol Développement and Cervinvest
- Advised ByoRNA and its founders on its €1.5 million pre-seed fundraising round
- Advised Derichebourg Aeronautics on its takeover of the companies of the SACI Technology group
- Advised AEQUITA on the acquisition of European olefins and polyolefins assets from the LyondellBasell group
- Advised Oxylabs in connection with its acquisition of Scrapingbee
- Jeantet assits Sirius Space Services in its acquisition pf S.E.R.M frome the Fives group
- Advised Centreon in connection with its acquisition of Quanta IO
- Advised the DLF Group in its joint-venture with the Florimond Desprez Group
- Advised the LOOPING GROUP in its acquisition of PARC SAINT-PAUL
Jeantet advised Groupe Ficade on the acquisition of Groupe Profession Santé
Paris, 11 March 2026 – Jeantet advised Groupe Ficade on the acquisition of Groupe Profession Santé (GPS), a B2B media group specialized in the healthcare sector and publisher notably of Le Quotidien du Médecin, Le Quotidien du Pharmacien and Infirmiers.com. This transaction forms part of Groupe Ficade’s external growth strategy. The group specializes in professional […]
| CORPORATE – M&A – PRIVATE EQUITY | TAX
Jeantet advises JIN on its investment in Qatane
Paris, February 2, 2026 – Jeantet advised JIN, an independent public relations and communications group, on the acquisition of a majority stake in Qatane, a firm specializing in citizen campaigns, executive support, and crisis communications. Combining strategic analysis and innovative digital solutions, Qatane has expertise in AI applied to strategic communications and is developing a […]
| CORPORATE – M&A – PRIVATE EQUITY
Jeantet advises JIN on the acquisition of Atchik
Paris, January 15, 2026 – Jeantet advised JIN, an independent public relations and communications group, on the acquisition of Atchik, a Toulouse-based company specializing in online content moderation and community management. Recognized for its expertise in data management and content moderation, Atchik counts major players such as L’Oréal, Carrefour, LVMH, and Radio France among its […]
| CORPORATE – M&A – PRIVATE EQUITY
Jeantet advised the founders on the sale of Rhis Solutions to Tol Développement and Cervinvest
Paris, January 12, 2026 –Jeantet advised Mr. Heikel Souissi, together with the other founders of Rhis Solutions, a publisher of software solutions for workforce time and activity management, notably for the quick-service restaurant sector (SaaS), on the sale of 100% of the company’s share capital to Tol Développement, a holding company already owning Truckonline and […]
| CORPORATE – M&A – PRIVATE EQUITY | TAX
Jeantet advised Diapason and PSG Equity on the acquisition of DeftHedge
Paris, December 18th, 2025 – Jeantet advised Diapason, a leading provider of SaaS treasury and financial risk management solutions, and its reference shareholder PSG Equity, on the acquisition of DeftHedge (Deft Softwares Europe), a SaaS platform specialized in foreign exchange and commodity risk management. Through this strategic acquisition, Diapason strengthens its technology offering by integrating […]
| CORPORATE – M&A – PRIVATE EQUITY | TAX | EMPLOYMENT | TECH & DATA
Quelques enseignements sur l’applicabilité de la procédure des avantages particuliers aux sociétés par actions simplifiées – Option Droit & Affaires 24/04/2024
Publication by Guillaume Fornier, partner. Read the article: here
| CORPORATE – M&A – PRIVATE EQUITY
Jeantet advises DERICHEBOURG AERONAUTICS on its acquisition of control of the SACI TECHNOLOGY GROUP
Paris, 10 September 2025 – Jeantet advised Derichebourg Aeronautics on its acquisition of control of the companies of the SACI Technology Group from its reference shareholder, Be Box Development. The SACI Technology Group companies are active in engineering and design services for the industrialization of products in the aeronautics industry. Through this acquisition, under which […]
Paris | CORPORATE – M&A – PRIVATE EQUITY
Jeantet advises Oxylabs in connection with its acquisition of Scrapingbee
Paris, July 4, 2025 – Jeantet advised Oxylabs, one of the market-leading companies in web scraping solutions, in connection with its acquisition of ScrapingBee, a French fast-growing web scraping company known for its developer-friendly solutions. Through this strategic acquisition, Oxylabs significantly expands the Oxylabs group’s ecosystem as well as its target clientele, now addressing direct […]
Paris | CORPORATE – M&A – PRIVATE EQUITY
Jeantet advises AEQUITA on the acquisition of european olefins et polyolefins assets from chemicals group LYONDELLBASELL
Paris, June 27, 2025 – Jeantet acted as French legal counsel to AEQUITA SE & Co. KGaA, a global industrial group headquartered in Munich, in connection with the signing of an agreement and entry into exclusive negotiations to acquire four European olefins and polyolefins assets from chemicals group LyondellBasell. The transaction covers plants located in […]
Paris | CORPORATE – M&A – PRIVATE EQUITY
JEANTET ASSISTS SIRIUS SPACE SERVICES IN ITS ACQUISITION OF S.E.R.M FROM THE FIVES GROUP
Paris, June 19, 2025 – Jeantet advises Sirius Space Services, a player in the space sector, on the acquisition of S.E.R.M (Société d’Études et de Réalisations Mécaniques), a historic precision machining site, accompanied by a strategic partnership with the Fives group and its subsidiary AddUp, a specialist in metal additive manufacturing. With this strategic acquisition, […]
Paris | CORPORATE – M&A – PRIVATE EQUITY
JEANTET ADVISES CENTREON IN CONNECTION WITH ITS ACQUISITION OF QUANTA IO
Paris, June 13, 2025 – Jeantet is advising Centreon, a trusted partner in digital performance monitoring, in connection with its acquisition of Quanta.io, a French software company renowned for its expertise in Web Performance and Green IT. Through this strategic acquisition, Centreon becomes the only private and independent vendor to offer an end-to-end observability platform […]
Paris | CORPORATE – M&A – PRIVATE EQUITY
JEANTET ADVISES THE DLF GROUP IN ITS JOINT-VENTURE WITH THE FLORIMOND DESPREZ GROUP
Paris, April 25, 2025 – Jeantet advised the DLF group in its joint venture with the Florimond Desprez group to create United Beet Seeds, a global player in the sugar beet seed industry. DLF Seeds A/S, a farmers’ cooperative headquartered in Denmark and present in 22 countries, the world’s leader in the breeding and production […]
Paris | CORPORATE – M&A – PRIVATE EQUITY | COMPETITION AND ECONOMIC LAW | TAX | EMPLOYMENT