The judgment below is reversed and the case is remanded to Seoul High Court.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. Regarding ground of appeal No. 1

A. Article 19(1) of the Monopoly Regulation and Fair Trade Act (hereinafter “Fair Trade Act”) provides that “No enterpriser shall agree with another enterpriser to jointly engage in any of the following acts that unfairly restrict competition (hereinafter “unfair collaborative act”) or allow another enterpriser to engage in such act”, and subparagraph 1 provides that “the act of determining, maintaining or changing the price.”

In addition, the main text of Article 22 of the Fair Trade Act provides that "the Fair Trade Commission may impose upon the relevant enterpriser a penalty surcharge not exceeding the amount calculated by multiplying the sales amount determined by Presidential Decree by 10/100." The main text of Article 9(1) of the former Enforcement Decree of the Monopoly Regulation and Fair Trade Act (amended by Presidential Decree No. 23864, Jun. 19, 2012) provides that "the sales amount determined by Presidential Decree" in the main text of Article 22 of the Fair Trade Act provides that "the sales amount determined by Presidential Decree means the sales amount of goods or services, or the amount equivalent thereto (hereinafter "related sales amount") in a particular business area during the period of violation, and Article 2 Subparagraph 8 of the Fair Trade Act provides that "the specific business area" refers to the area where a competitive relation can be established either by the object, stage or region of the transaction or by the competitive relation."

In light of the contents, form, system, and legislative intent of the relevant laws, Article 19 (1) 1 of the Fair Trade Act.