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

The grounds of appeal are examined.

As to the Defendant’s ground of appeal

A. Comprehensively taking into account the adopted evidence, the lower court acknowledged the Defendant’s first priority in making a collective agreement with the Defendant on September 30, 2009, that the Plaintiff, a trade union organized by the Defendant’s employees, stipulated that “the Defendant shall deposit 5% of the pre-paid interest with the intra-company labor welfare fund every year in accordance with the former Act on the intra-company labor welfare fund (amended by Act No. 10361, Dec. 9, 2010; hereinafter “instant agreement”) for the promotion of the welfare of the Plaintiff’s union members,” and that “the Fund Council (hereinafter “Council”) of the Korea District Heating Corporation established under the former Act on the Welfare Fund (hereinafter “instant welfare fund”) shall contribute the amount equivalent to 20% of the pre-paid interest to the Fund if the guidelines for compilation of the budget of the Ministry of Strategy and Finance in the year 2010 for each person’s total amount equal to or more than 1% of the pre-paid interest to the Fund.

In full view of the above facts of recognition, the court below held that the agreement of this case is a contract for the plaintiff, the defendant's abortion, and the third party who entered into the welfare fund of this case with the third party as the third party, and that the defendant has a duty to contribute to the welfare fund of this case 5% of its relationship with the plaintiff in case of the occurrence of the pre-payment profit in the pertinent year. In light of the principle of interpretation of the disposition document and collective agreement, the part of the contract of this case "in accordance with the former Welfare Fund Act" in the Framework Act is the same as Article 61 (1), Article 61 (2) and Article 13 (1), (2) of the former Welfare Fund Act.