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Siqueira Castro – Advogados

Work +55 11 3704 9840

Guilherme Dantas

Work +55 11 3704-9840
Siqueira Castro – Advogados

Work Department

São Paulo Office



Areas of activity
• Corporate Law
• Mergers and Acquisitions
• Contracts
• Private International Law
• Commercial Law
• Competition Law
• Banking Law
• Telecommunications
• Civil Law
• Court-Supervised Reorganization and Bankruptcy
• Media and Entertainment Law
• Third Sector


• Parner with Siqueira Castro – Advogados
• Founder and Partner of Dantas, Lee, Brock & Camargo Advogados.
• Partner with Manhães Moreira Advogados
• Consultant with KPMG
• Legal representative, board of directors member and executive of various Brazilian subsidiaries of multinationals, in particular in the technology sector
• Board member of third-sector entities in the areas of education and culture
• Former visiting professor at UniSantana – Tax law
• Former visiting professor at UniSantana – Foreign trade law
• Teaching assistant in constitutional law at PUC-Campinas
• Teaching assistant in procedural law at PUC-CAmpinas


Portuguese, English, Spanish and German.


• Member of the Brazilian Bar Association, São Paulo State Chapter
• Member of the Brazilian Bar Association, Rio de Janeiro State Chapter
• Member of the Association of Lawyers of São Paulo – AASP
• Member of the International Bar Association – IBA
• Representative of Brazil with the Association of International Tax Consultants - AITC
• Former Board Member of the AITC
• Former Board Member of Avrio Avocati


• Law Degree from Pontifical Catholic University of Campinas (PUC-Camp) Law School, in 1996
• Postgraduate specialization in telecommunications law from Getulio Vargas Foundation (FGV/SP)
• Postgraduate specialization in economic law from Getulio Vargas Foundation (FGV/SP)


Bankruptcy and restructuring

Within: Bankruptcy and restructuring

Siqueira Castro – Advogados has a broad practice that spans restructurings, renegotiation of debt and credit recovery, with experience acting for both debtors and creditors. In one major case, André Gondinho and Guilherme Dantas are acting as one of the main external counsels to Avianca in the company’s judicial reorganisation. Recent internal developments included the promotion of Alexandre Wider and Marina Magalhães Gomes Ramacciotti to partner.

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Competition and antitrust

Within: Competition and antitrust

Recommended firm Siqueira Castro – Advogados acts for individuals and companies in cartel investigations before CADE. Competition and criminal law expert João Daniel Rassi is recommended. Marina de Araújo Lopes, whose practice encompasses competition, compliance and regulatory law, made partner in 2018. Guilherme Dantas and Heitor Faro de Castro co-head the department.

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Corporate and M&A

Within: Corporate and M&A

Siqueira Castro – Advogados distinguishes itself through its extensive office network across Brazil. The sizeable team is also equipped to handle cross-border mandates. In addition to its transactional workload, the team regularly advises clients on corporate and contractual matters, and its full-service offering allows it to provide comprehensive coverage of other areas, including competition and tax. For example, Carlos Fernando Siqueira Castro and Fábio Korenblum advised an engineering company in a range of business law issues, including environmental and regulatory matters. Elsewhere, a cross-departmental team that included corporate partner Sérgio Ricardo Fogolin assisted a public-listed company with the acquisition of two companies. Marina Magalhães Gomes Ramacciotti made partner in 2019. Guilherme Dantas is a key contact.

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