Alerion > Paris, France > Firm Profile

75007 PARIS

France > Construction Tier 2

Alerion's real estate and construction practice is routinely instructed by developers, corporations and insurance funds seeking advisory, transactional and contentious support on a range of construction projects. The group is co-directed by a trio of partners: firm co-founder Philippe Mathurin, who is well-versed in both advisory construction work and litigation; Nathalie Dupuy-Loup, who brings expertise to constructors’ liabilities and construction insurance matters; and Fahima Gasmi, whose practice spans construction and environmental law.

Practice head(s):

Philippe Mathurin; Nathalie Dupuy-Loup; Fahima Gasmi


‘The team is extremely expert in construction and construction insurance. A rare strategic approach in this area which is intelligent and reassuring.’

‘Philippe Mathurin and Fahima Gasmi are experts, invested in their clients.’

‘Responsiveness, customer awareness and business knowledge.’

‘Fahima Gasmi: responsive, competent.’

France > Insurance Tier 3

Alerion assists insurance companies, brokers and insured entities with both advisory and contentious matters, with strong recent experience in claims in the construction, transport and healthcare sectors. Philippe Mathurin, whose areas of expertise include industrial risks and construction insurance, Nathalie Dupuy-Loup, who handles personal and workplace injury-related claims, and construction-focused Fahima Gasmi lead the team.

Practice head(s):

Philippe Mathurin; Nathalie Dupuy-Loup; Fahima Gasmi


‘The management of the file by one or even two lawyers allows us to receive a good overall perspective of the issues specific to the case. The team’s expertise is based on solid technical skills but also on a direct approach with regard to the point of law to be addressed. By explaining the problem raised and the response proposed, they ensure that the strategy is perfectly understood and validated by the client.

‘Nathalie Dupuy-Loup and Philippe Mathurin are my main contacts. They understand the facts and the legal and commercial issues, propose a strategy (based on the anticipated means of action, jurisdictional issues, etc.) and adapt it as the situation evolves, which contributes to the optimal defence of the client’s interests.’

‘The availability and accessibility of the lawyers constitutes an asset in the formation of the lawyer-client team: the work is distributed and carried out as a team, with a strong capacity to integrate into the client’s company, including with people who are not used to interacting with legal professionals.’

France > Private equity: venture/growth capital Tier 3

Practice head(s):

Pierre-Olivier Brouard; Vincent Poirier; Antoine Rousseau; Christophe Gerschel

Other key lawyers:

Benoît Deramoudt; Karine Khau-Castelle; Pauline de Roquefeuil


‘Responsiveness, availability, quality of advice.’

‘Alerion’s support was extremely qualitative – very responsive team – ability to adapt to specific issues with pragmatic advice, allowing effective solutions to be found while bringing the parties together – coverage of the all subjects, if necessary by requesting relevant internal specialists.’

‘Pierre-Olivier Brouard: very senior but remains available; always aware of the progress of projects; good business sense to advance projects and find solutions. Benoît Deramoudt, Karine Khau-Castelle, and Pauline de Roquefeuil – very precise and exhaustive, move subjects forward, cover all points, know how to manage complexity.’

‘Skill, reactivity, quality of documents, personalised advice.’

‘Pierre-Olivier Brouard – competent, humble, available, organized.’

‘Seriousness, availability, commitment, creativity, experience.’

Key clients

Hugues de Rouville

Isatis Capital

EDF Pulse

Adaxtra Capital

TechLife Capital

BPI France Investissement & Eurazeo



Check & Visit


Work highlights

  • Assisted Ekoscan Integrity with the raising of €23m from three funds: Abénex, EDF Pulse Ventures, and its historical investor, ALIAD.

France > Industry focus: IT and internet  Tier 4


Practice head(s):

Corinne Thiérache; Frédéric Saffroy


‘Responsiveness, availability and efficiency of the team, which stands out for its very strong involvement in the relationship with its clients.’

Key clients

Essentiel Notaires

Organisation et Développement (OMNES EDUCATION)


AEF info

Work highlights

  • Assisted Essentiel Notaires with the development and commercialisation of its proprietary solution Quai des Notaires.
  • Advising the Nuxe group following a cyberattack, including advising on mitigation measures to be taken regarding the breach of confidential data.

France > Insolvency Tier 4

Under the leadership of Gilles Podeur, the restructuring and insolvency practice at Alerion assists clients across a spectrum of matters. Leveraging synergies with other practices, including M&A and financing, enhances the team’s capability to handle intricate transactions requiring cross-disciplinary expertise. Consequently, the team is actively engaged in mandates of varying sizes, from landmark restructurings of large companies, such as CNIM and Alinea, to mid-sized restructurings. The practice's expertise extends beyond transactional work to encompass out-of-court debt renegotiation, insolvency proceedings, and associated litigation, often with a significant cross-border dimension.

Practice head(s):

Gilles Podeur

Key clients


Ipsa Holding

Work highlights

  • Advised the shareholder of Pimkie regarding its sale pursuant to a court-sanctioned conciliation agreement.

France > Intellectual property: Trade marks and designs Tier 4

France > Mergers and acquisitions Tier 5

Practice head(s):

Pierre-Olivier Brouard; Christophe Gerschel; Vincent Poirier; Antoine Rousseau


‘Excellent team’.

‘The team is extremely available, competent and a deal maker. They have a perfect mastery of all communication tools/means, making it very easy to work collaboratively on documents and exchanges. ’

‘Pierre-Olivier Brouard is very pleasant to work with.’

Key clients

Groupe Médiamétrie

Groupe Bolloré

The Blockchain Group

Groupe Faurecia


Groupe Cyllene

Santarelli and its shareholders


Estève & Cie

La Ruche qui dit Oui

Ponticelli Group



Association Familiale Mulliez (AFM)

Groupe Bureau Vallée

Miles Partnership


Work highlights

  • Advised the seller (Association Familiale Mulliez – AFM) of the retail brand Pimkie during its cession to a consortium.
  • Advised Parella on its acquisition of The Tenant Solution.
  • Advised Médiamétrie, seller, on the acquisition by Ipsos of Omedia.

France > Environment

Philippe Mathurin jointly leads the team at Alerion alongside Fahima Gasmi, who is noted for her expertise in industrial environmental law, supporting economic operators during all stages of the operation of industrial sites.

Alerion is an independent law firm created in 2003, specialising in international business.  Constantly growing, it now has 18 partners and a total of over seventy lawyers. Based in Paris, the firm works both for French clients who are expanding internationally and foreign clients investing in France, advising them and assisting them in disputes. Over time, the firm has developed skills in the main areas covered by business law. The firm’s partners advise clients operating in most sectors of French and international economic life. Over the years, they have also developed specific and cross-disciplinary knowledge of certain areas of activity such as sports, pharmaceuticals & biotechnology, the digital economy, real-estate, and aerospace. The firm works for a wide variety of clients (large French and international groups, French subsidiaries of large international groups, listed companies or small and medium-sized businesses, start-ups, investment funds, associations, public institutions, local authorities, family offices, etc.). To fulfil its client’s foreign law requirements, Alerion has correspondents in most countries.

Department Name Email Telephone
Photo Name Position Profile
Jacques Bouyssou photo Mr Jacques Bouyssou Partner, Head of Litigation, arbitration and white-collar crime department and the Spanish…
Pierre-Olivier Brouard photo Mr Pierre-Olivier Brouard Partner, head of Corporate law department
Jean-Christophe Brun photo Mr Jean-Christophe Brun Partner
Stanislas Curien photo Mr Stanislas Curien Partner
Nathalie Dupuy-Loup photo Ms Nathalie Dupuy-Loup Partner
Fahima Gasmi photo Ms Fahima Gasmi Partner in real estate/construction, environment, industrial risks, insurance and public procurement departments.
Christophe Gerschel photo Mr Christophe Gerschel Partner
Nicola Kömpf photo Ms Nicola Kömpf Partner in German Desk
Sibylle Mareau photo Ms Sibylle Mareau Partner in Litigation, arbitration and white-collar crime
Philippe Mathurin photo Mr Philippe Mathurin Partner, head of department
Jacques Perotto photo Mr Jacques Perotto Partner
Philippe Pescayre photo Mr Philippe Pescayre Managing Partner
Gilles Podeur photo Mr Gilles Podeur Partner, Head of the Restructuring & Insolvency department
Vincent Poirier photo Mr Vincent Poirier Partner
Catherine Robin photo Ms Catherine Robin Partner
Antoine Rousseau photo Mr Antoine Rousseau Partner
Frédéric Saffroy photo Mr Frédéric Saffroy Partner
Corinne Thiérache photo Ms Corinne Thiérache Partner, Head of department
Stanislas Vailhen photo Mr Stanislas Vailhen Partner in Tax Law
Number of partners : 18
Number of lawyers : 70
IBA (International Bar Association)

Since its creation, Alerion has always been leaning toward international business. In the firm, we have lawyers who are members of international bars. In total, at Alerion it is possible to work in 4 different languages: French, English, German and Spanish, which facilitates communication with all clients. Alerion assists foreign clients with their various requirements, whether it is for setting up a business abroad, for the realization of a transaction or for the restructuring of a company.

Our dual-qualified lawyers

Alerion have 3 lawyers in our firm who are dual Bars registered: Nicola Kömpf is a member of the Paris and Berlin Bars, Friedriech Niggemann is a member of the Paris and Düsseldorf Bars, Jacques Bouyssou is a member of the Paris and Madrid Bars.

Also, Alice Bastien, admitted to the Paris Bar as of 2022, is currently awaiting her admission to the New York Bar.

Active member of the IBA (International Bar Association)

Alerion has been a member of the IBA for more than 10 years and regularly participates in the many events organised by the IBA. Jacques Bouyssou, partner at Alerion, is co-chair of the IBA litigation committee, and several lawyers at Alerion are also members of different IBA committees.

A firm with a strong international focus

The firm has active German and Spanish Desks that provides German-speaking and Spanish-speaking clients with legal services in their own languages, adapted to their cultural specificities. Alerion has also developed extensive experience on the African continent where it has a network of reliable referral firms. The firm also has a long-time partnership with the Canadian-based law firm Lette.

Alerion, aware of the need for local beekeepers, is committed to the preservation of the ecosystem by sponsoring a beehive in the Paris region thanks to the association Un toit pour les abeilles.

The firm has also implemented several practices within the firm:

  • Providing our team with recycled paper.
  • Using an external service provider to collect used paper and recycle it.
  • Paper consumption has been significantly reduced thanks to the successive lockdown that have accelerated the digitalisation of processes and we didn’t go back to the way it was before.
  • Thanks to a partnership with Le Cercle, the meal trays are environmentally friendly. Indeed, Le Cercle recovers the meal trays to reuse them, all in order to be part of a more eco-responsible approach.
  • The firm distributes mugs to its team members to encourage them to stop using single-use cups and bottles.
  • The Christmas tree is originated from France and horticulturally grown.

The firm’s approach to society

Alerion acts for its co-workers’ well-being at work:

  • The firm carried out sessions on the prevention of work-related illnesses by videoconferencing with an external service provider.
  • Following the coronavirus crisis, a remote working policy was established.
  • A fruit basket is available to employees twice a week in the office.
  • The firm has a fair gender ratio : we have 50.6% women and 49.4% men as of 2021.
  • Career and development opportunities are encouraged. Since its creation, Alerion has seen seven associates become partners and continues to see its associates evolve within the teams.
  • In addition, a quality commission is held every two months to discuss and improve well-being within the firm.