Eiji Kobayashi is a partner in the Corporate & Securities practice in Mayer Brown's Tokyo office.

Eiji has more than 20 years of experience in representing the world’s leading industrial conglomerates, including technology, automobile, real estate, and life sciences companies and financial institutions in cross-border mergers and acquisitions, corporate, projects, disputes and regulatory and investigation matters. His practice focuses on complex cross-border corporate and M&A matters, real estate, and other project matters. He also has wide-ranging experience representing companies and individuals in regulatory investigations matters, especially in the industrial, technology, life sciences, aviation and financial institutions industry sectors.

Earlier in his career, Eiji worked at a major US M&A law firm, as co-head of the cross-border transactions group at the largest law firm in Japan, and as the chair of the corporate/M&A practice group in Japan for a global law firm. He has represented some of the world’s leading corporations.

Spoken Languages

  • English
  • Japanese


Mergers & Acquisitions

  • A medical optics company in its US$450 million cash acquisition of the surgical ophthalmic business of an American multinational pharmaceutical corporation.
  • An insurance company that provides clients with medical care, cancer, specified disease, death, life and group health insurance services throughout Japan in its US$963 million acquisition of a leader in property and casualty insurance, group benefits, and mutual funds with more than 200 years of expertise.
  • A Japanese food manufacturing company based in Tokyo with overseas operations and listed on the on the Nikkei 225 in its US$215 million acquisition of flour milling facilities from an American packaged foods company.
  • A Japanese telecommunications operator in the US$965 million cash acquisition by a British multinational telecommunications holding company of a provider of broadband and internet, voice, networking, and other related solutions, in which the Japanese company was a strategic shareholder, and the establishment of a related joint venture and alliance between the two.
  • A Japanese multinational ceramics and electronics manufacturer headquartered in Kyoto, Japan in its 100% strategic acquisition of a US-based solid tool manufacturing and sales company in an effort to strengthen its global business and expand its cutting tool business in North America.
  • A Japanese multinational automobile manufacturer in its global restructuring of its battery business.
  • A Japanese public-private partnership fund, in its proposed investment in relation to an acquisition of a French nuclear power company.
  • A member of a US-Japan consortium for a proposed nuclear power plant construction project in Abu Dhabi.
  • A banking holding company headquartered in Tokyo, Japan in its US$500 million investment in an American global investment management corporation based in New York City.
  • A Japan-based company mainly engaged in the financial business in its US$1.3 billion acquisition of an aviation company to add approximately 70 commercial aircrafts to its aircraft lease business.
  • The financial advisor in relation to an acquisition of a majority interest in a Korean online game developer listed on NASDAQ.
  • A major Japanese shipping company forced to enter bankruptcy in 2015, in registering the Japanese bankruptcy proceedings in England, the US, Canada, Australia, Canada and South Africa.
  • A life science company with a more than 150-year history in its dispute resolution matters in Japan.
  • An American multinational pharmaceutical corporation headquartered in New York City on its US$33 million acquisition of a minority stake in an American multinational pharmaceutical corporation headquartered in New York City and its drug-discovery collaboration with a UK group to develop new medicines aimed at a handful of biological targets that may play a role in multiple diseases.
  • A subsidiary of one of the largest telecommunications company in the world in its strategic investment in a telecommunications, internet, and digital service holdings company in the Philippines.
  • A Japan-based consumer credit services company in its strategic investments in the consumer finance and lease businesses in Indonesia.
  • A French multinational automobile manufacturer established in 1899 relating to a broad strategic alliance among several others in the sector.

Regulatory and Compliance/Investigations 

  • A senior executive of a major Japanese technology and manufacturing company in a US-based regulatory investigation of alleged product safety issues, including direct negotiations with the US Department of Justice, the Federal Bureau of Investigations and the Food and Drug Administration.
  • A major European automotive company in relation to a global safety matter involving Japanese parts suppliers.
  • A Japanese industrial company in a US and European investigation relating to aviation safety issues, including direct negotiations with the Federal Aviation Administration, European Aviation Safety Administration and major aircraft manufacturers and airlines.
  • A major Japanese company in its investigation of accounting and commercial irregularities in its overseas subsidiaries.
  • An insurance company in its investigation of insurance claims made under representations and warranties insurance for M&A transactions.
  • A Japanese financial institution in an alleged violation of trading rules in Japan and in Hong Kong.
  • An individual of a major financial institution in an alleged violation of trading rules.
  • An individual of a major Japanese technology and manufacturing company in a US-based regulatory investigation of alleged FCPA and related laws occurring outside the US.


  • A major Japanese technology and manufacturing company in its M&A transactions in China and other parts of Asia.
  • A major Japanese industrial conglomerate in competition law analysis of its supply chains joint ventures.
  • A major Japanese consumer foods company in competition law driven M&A transactions, including direct negotiations with the US Department of Justice.
  • A major Japanese telecommunications carrier in global competition law issues in its joint venture with a European-based telecommunications carrier.

International Trade/Sanctions & Export Controls

  • One of the largest technology companies based in Japan in their review and establishment of an internal policy relating to export controls.
  • One of the largest financial institutions based in Japan in the review of economic sanctions exposure in a proposed credit transaction in the Middle East.
  • A publicly listed company in Japan in relation to US government contracts with the Department of Energy.
  • A general trading company in Japan in relation to the cross-border transportation of uranium-enriched materials.
  • A number of Japanese industrial companies in their M&A transactions involving export controls and economic sanctions review, including companies in the aerospace/transportation, technology, life sciences and food industries.


The University of Texas at Austin, BBA
with honors

The University of Texas School of Law, JD


  • Japan (Gaikokuho Jimu Bengoshi)
  • Texas