Martínez de Hoz & Rueda is ‘intimately familiar’ with Argentina’s oil and gas regulatory landscape and assists companies such as Pan American Energy Group and Delta Patagonia with transactional and litigation matters. The practice provides support with the acquisition of large offshore and onshore gas-producing fields, as well as the financing and construction of LNG facilities and pipeline projects. The team also assists with the sale of crude oil-producing assets and the granting of concession rights. Additionally, the firm advises clients on obtaining hydrocarbon exploration permits and defends them in collective actions initiated by NGOs and local municipalities seeking to block these projects. The practice is led by José Alfredo Martínez De Hoz, who played a key role in developing Argentina’s domestic and export gas markets during the country’s privatisation and deregulation; Pablo Rueda, who assists producers, transporters, and distributors of hydrocarbons; and Tomás Lanardonne, who specialises in upstream, midstream, and downstream projects. Among the second-line of younger partners, Marcos Blanco is effective in tender processes and contract negotiations, while Juan Cruz Azzarri brings substantial arbitration and litigation experience in the oil and gas sector to the practice. Jimena Vega Olmos left the firm in July 2025.
Legal 500 Editorial commentary
Testimonials
Collated independently by Legal 500 research team.
‘MHR is widely recognised for its expertise in oil and gas matters. Its professionals are intimately familiar with industry regulations and practices and are frequently consulted by hydrocarbon-producing companies.'
‘They stand out for their commitment to their clients, knowledge and marked practicality, all while ensuring clients achieve their desired objectives.'
'The lawyers provide exceptional work and are available all the time.'
'Excellent professionals, knowledgeable, know how to treat their clients and are available at any time. They answer quickly.'
'Extensive knowledge of the industry, local practices, and international practices. Additional service presence in Neuquén.'
'Great knowledge of the industry. Great capacity for work and on-time delivery. Extensive involvement in projects.'
Key clients
- CAPSA/CAPEX
- Chevron Argentina
- Chevron Corporation
- Chevron South America (Peru)
- Chevron Uruguay
- Compañía de Hidrocarburo No Convencional
- Compañía General de Combustibles
- Delta Patagonia
- Energy Transfer
- Equinor Argentina
- ExxonMobil Exploration Argentina / ExxonMobil Argentina Offshore Investments
- Harbour Energy
Work highlights
Advised Chevron in its negotiations with YPF, the Argentine national oil company, Pan American Energy, Pampa Energía, Vista Energy, Shell and Pluspetrol concerning several agreements for the development of the “Vaca Muerta Sur” oil pipeline through a project company named VMOS.
Represented ExxonMobil in two transactions: (i) the sale of its primary crude oil producing asset to Pluspetrol, which included its stake in Oldelval; and (ii) the sale of its leading natural gas producing field to YPF, along with the concession rights to the 'Sierra Chata' block.
Advising YPF concerning the development of a greenfield integrated LNG project, which now includes the participation of Shell, following the exit of Petronas, the Malaysian national petroleum company.
Lawyers
Hall of Fame
The lawyers at the very top of the profession, widely known and respected by peers and clients for their longstanding involvement in market-leading work.
Pablo Rueda
Leading partners
The strongest partners in their field, leading on market-leading deals and endorsed by peers and clients alike.
Tomás Lanardonne
Next Generation Partners
Junior partners with significant recognition from clients and peers in the market and key roles on multiple matters.
Practice head
José Alfredo Martínez de Hoz; Pablo Rueda; Tomás Lanardonne
Other key lawyers
Marcos Blanco; Juan Cruz Azzarri