Sang Oh Jeon

Antitrust & Competition

Cartel

Merger Filings

Unfair Affiliate Transactions

Subcontracting

Distribution

Antitrust & Competition Compliance

Antitrust & Competition Litigation

Abuse of Market Dominance

Unfair Trade Practices

Antitrust & Competition Litigation

Corporte Governance ∙ Conglomerates ∙ Holding Companies

Sang Oh Jeon is a Head of Antitrust & Competition Group (partner) at Yoon & Yang LLC, his and main practice area is antitrust & competition.

Mr. Jeon has advised not only major Korean conglomerates such as Samsung, Hyundai Motor, SK, LG, Hanhwa, GS, LS, and Hyundai Department Store but also major multinational corporations such as UBS and Panasonic in responding to the Korea Fair Trade Commission’s investigations regarding various domestic and foreign cartel cases; unfair trade practice cases; violation of the Subcontracting Act; violation of the retail business law; and the franchise business law. In addition, he handles responses to franchise business law investigations, litigations, and consulting for major domestic franchises such as Paris Baguette, Kyochon, BBQ, Mom's Touch, and Puradak. He has been recognized as a Best Lawyer by JoongAng Daily & Korea In-house Council Association (2024), a Client Choice Awards winner by Lexology (2024-2025), a Leading Individual by Chambers and Partners (2024-2025), a Litigation Star by Benchmark Litigation (2024), a Lawyer of the Year (2020) and Leading Lawyer (2020-2025) by Legal Times.

Admitted to bar, Korea (2008)

[Books]

Subcontracting Law (practical guide to corporate transactions), Fair Competition Federation (Co-author, 2020)

[Academic Papers]

Korea Chapter, Antitrust Litigation, Chambers Global Practice Guides, Chambers and Partners (Co-author, 2024)

Competition Law in South Korea: Overview, Practical Law, Thomson Reuters (Co-author, 2023)

Korea Chapter, Merger Control, Chambers Global Practice Guides, Chambers and Partners (Co-author, 2023)

Korea Chapter, Mergers, Cases and Precedents, Global Competition Review (co-author, 2021)

Korea Chapter, Cartels, Cases and Precedents, Global Competition Review (Co-author, 2021)

Korea Chapter, Franchise Law Review, Law Business Research (Co-author, 2017-2019)

Korea Chapter, e-Commerce, Getting the Deal Through, Law Business Research (Co-author, 2017-2019)

Korea Chapter, Know how - Immunity, Sanction & Settlements, Global Competition Review (Co-author, 2015-2020)

Applicable Law regarding Tender Cartel and Calculation of Related Sales – Case Study on Economic Law Vol. 9, Economic Law Case Study Association (Co-author, 2015)

Half Price Real Estate Agent’s Commission and Antitrust Law – Competition and Law, Legal Times (2015)

[Cartel]

KFTC investigation into cartel related to LTV interest rates

KFTC investigation into cartel in the government bond market

KFTC investigation into cartel in indemnity insurance

KFTC investigation and administrative litigation regarding cartel in the broiler chicken industry

Administrative litigation over vaccine bid-rigging

KFTC investigation and administrative litigation on cartel in steel scrap purchasing by rebar companies

KFTC investigation into cartel in aluminum bidding for Hyundai-Kia Motors

KFTC investigation into cartel in rebar sales by steelmakers

KFTC investigation into cartel by Japanese aluminum capacitor manufacturers

International cartel case involving fuel surcharges

International cartel case involving marine hoses

KFTC investigation into cartel in government procurement of system air conditioners (home appliances cartel)

International cartel case involving LIBOR and other interest rates

KFTC investigations into cartel in construction projects such as Honam High-Speed Rail, Gyeongin Canal, and Daegu Metro

[Unfair Support & Improper Provision of Benefits]

KFTC investigation into improper benefit provision to related parties by Hanwha Group affiliates

KFTC investigation into unfair support among SPC Group affiliates

KFTC investigation into unfair support and improper benefit provision by Hanjin Group affiliates

KFTC investigation into improper benefit provision to related parties by Taekwang Group affiliates

KFTC investigation into unfair support among LS Group affiliates

KFTC investigation into unfair support among E-Land Group affiliates

KFTC investigation into unfair support among HiteJinro Group affiliates

KFTC investigation into unfair support among Dongwon Group affiliates

KFTC investigation into unfair support among affiliates of Group S

KFTC investigation into unfair support among affiliates of Group B

KFTC investigation into unfair support among affiliates of Group D

KFTC investigation into unfair support among affiliates of Group H

Compliance advisory services including establishment of internal transaction review committees for major domestic companies

[Subcontracting Act]

KFTC investigation into unfair subcontracting practices by home appliance companies

KFTC investigation and administrative litigation regarding unfair subcontracting by Samsung SDI

KFTC investigation into unfair subcontracting by LG Chem

KFTC investigation into unfair subcontracting by Hanwha Systems

KFTC investigation into unfair subcontracting by STX Engine

KFTC investigation into unfair subcontracting by Dongwon Loex

KFTC investigation into unfair subcontracting by Daewoo Shipbuilding & Marine Engineering

KFTC investigation into unfair trade practices by convenience store franchisors

Legal advisory on bid participation restrictions for major companies

[Franchise Business Act]

Legal representation and/or advisory in franchise margin lawsuits involving BR Korea, Goobne Chicken, Puradak, Frank Burger, Genesis BBQ, and others

KFTC investigation and administrative litigation involving Genesis BBQ’s violation of the Franchise Business Act

KFTC investigation and administrative litigation involving Puradak’s violation of the Franchise Business Act

KFTC investigation and administrative litigation involving BR Korea’s violation of the Franchise Business Act

Constitutional petition regarding the enforcement decree of the Franchise Business Act (franchise margin)

[Unfair Trade Practices & Agency Act]

KFTC investigation into Agency Act violations by automobile companies

KFTC investigation into Agency Act violations by tire companies

KFTC investigation into unfair trade practices by electric bus manufacturers/importers

Legal response to KFTC investigations and damages lawsuits involving unfair trade by telecom companies and smartphone manufacturers

Damages lawsuit related to unfair trade practices by beverage company N

KFTC investigation into Agency Act violations by footwear importer A

Compliance advisory on the Agency Act for affiliates of Groups S and E

[Large-Scale Retail Business Act]

KFTC investigation into violations of the Large-Scale Retail Business Act by Daiso

KFTC investigation into violations by Wemakeprice

KFTC investigation into violations by Hyundai Department Store

KFTC investigation and consent decision involving Korea Seven

Legal and compliance advisory for department stores, outlets, convenience stores, and home shopping companies including H, E, S, and G

[Fair Trade-Related Damages Litigation]

Damages litigation involving elevator cartel

Damages litigation involving cable manufacturers' cartel

Damages litigation related to subcontracting violations by a logistics company

Damages litigation related to vaccine bid-rigging

Damages litigation involving cartel in plate and coil transportation

[Compliance]

CP (Compliance Program) consulting for Hyundai Motor Group affiliates

CP consulting for LG Group affiliates

CP consulting for Taekwang Group affiliates

CP consulting for Hanwha Group affiliates

CP consulting for Toss Group affiliates

CP consulting for KT Group affiliates

2008-present: Yoon & Yang LLC

2025-present: Outside Director, Oheim & Company Co.,Ltd.

2024-present: Director, Korea Competition Law Association

2022-present: Outside Director, Hyundai BNG Steel

2021-present: Fair Trade Lecturer, Korean Institute of Certified Public Accountants

2021-present: Lecturer, Fair Trade Training Institute, Seoul Bar Association (Subcontracting Act)

2021-present: Board Member, Gangnam-gu Sports Council

2018-present: Non-Government Advisor, International Competition Network

2014-present: Legal Advisor and Board Member, Korean Federation of Middle & High School Athletic Associations

2014-present: Lecturer, Korea Productivity Center (Fair Trade Act, Subcontracting Act)

2012-present: Lecturer, Fair Competition Federation (Fair Trade Act, Subcontracting Act, Large Retail Business Act)

2013-15: Lecture, Maeil Economy Education Center (Lage Retail Business Act, Franchise Business Act)

2005-08: Public Attorney, Ministry of Justice

Yonsei University Graduate School of Business

(Franchise Business Coursework completed)

2014

University of Southern California Gould School of Law

LL.M.

2013

Seoul National University School of Law

(Fair Trade Law Research Coursework completed)

2010

Hanyang University, Graduate School of Law

(International Trade Law Coursework completed)

2010

Judicial Training & Research Institute

2005

Seoul National University, Psychology

B.A.

2003

Leading Individual, Competition/Antitrust

Chambers and Partners Asia-Pacific

2024

Client Choice Awards, Competition

Lexology

2024

Litigation Star, Competition/antitrust

Benchmark Litigation Asia-Pacific

2024

Lawyer of the Year, Antitrust & Competition

Legal Times

2020

Leading Individual, Competition/Antitrust

Chambers and Partners Asia-Pacific

2025

Client Choice Awards, Competition

Lexology

2025

Litigation Star, Competition/antitrust

Benchmark Litigation Asia-Pacific

2025