The appeal is dismissed.

The costs of appeal are assessed against the Intervenor, and the remainder are assessed against the Intervenor.

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

1. Ground of appeal No. 1 (pointing out a misapprehension of legal principles as to Article 77-4 (6) of the former Act on the Maintenance and Improvement of Urban Areas

A. Article 77-4 of the former Act on the Maintenance and Improvement of Urban Areas and Dwelling Conditions for Residents (wholly amended by Act No. 10268, Apr. 15, 2010; wholly amended by Act No. 14567, Feb. 8, 2017; hereinafter “former Act”) provides that the head of a Si/Gun may provide for public management to support the implementation process of a rearrangement project prescribed by City/Do municipal ordinance in order to enhance transparency and efficiency of a rearrangement project, while prescribing methods, procedures, etc. for implementing the project by City/Do municipal ordinance.

According to delegation, Article 48 (4) of the Seoul Metropolitan Government Ordinance on the Improvement of Urban and Residential Environments (amended by Ordinance No. 5007, Jul. 15, 2010; hereinafter referred to as the "Ordinance of this case") provides that the Mayor shall set the standards for the method, etc. of selecting a rearrangement project management contractor.

Article 4(1) of the Addenda to the instant Ordinance provides that “any disposition, procedure, and other actions conducted under the previous provisions at the time this Ordinance enters into force shall be deemed to have been conducted under this Ordinance.”

According to the delegation of the instant Ordinance, the criteria for the selection of a management entity specialized in the management of a rearrangement project (which was publicly notified by the Seoul Special Metropolitan City Notice No. 2010-274 on July 15, 2010 and implemented from July 16, 2010; hereinafter “instant criteria for selection”) were publicly notified. Article 2 of the Addenda provides that “The same shall apply from the portion of a rearrangement project for which no management entity is selected at the general meeting at the time of the implementation of the instant criteria.”

In full view of the contents, structure, legislative intent, etc. of the above provisions, the following conclusions can be derived.

(1) As of July 16, 2010, with respect to an improvement project, the general meeting of which does not select a specialized management businessman of rearrangement projects, this case.