1. All of the plaintiffs' claims are dismissed.

2. The costs of lawsuit are assessed against the plaintiffs.

1. Basic facts

A. The plaintiffs and the defendant are insurance companies with the main purpose of non-life insurance business and marine insurance business.

On the other hand, A Co., Ltd. (hereinafter “A”) is an insurance intermediary that mediates the business of coverage against reinsurance to a foreign reinsurance company in order to diversify the risks of insurance contracts concluded by a domestic insurance company at the request of the domestic insurance company.

B. The concept of advance refund guarantee insurance and ordinary underwriting procedure 1) The term "Advance refund guarantee insurance" means, where a shipbuilding contract is concluded between a person placing an order, such as a foreign ship company, etc. and a shipbuilding company, the person placing an order will pay advance payment based on the base price during the shipbuilding process. In the event of an accident not delivered to a ship due to a cause attributable to a shipbuilding company, the person placing an order refers to the insurance guaranteeing the advance refund paid by a non-life insurance company at the request of a shipbuilding company in order to guarantee the refund of advance payment paid before the occurrence of the accident. 2) In the above advance refund guarantee insurance, there exists a form of guaranteeing the performance of advance refund liability owed by a financial institution to a client by a shipbuilding company and the non-life insurance company at the time of the occurrence of an accident not delivered to a ship due to a cause attributable to a shipbuilding company (the amount of advance to be returned by a shipbuilding company is a large amount, and most of them require a financial institution at the time of concluding a shipbuilding contract from the client’s side.

3. On the other hand, where a domestic non-life insurance company enters into an advance refund guarantee insurance contract as above, it shall pay large amount of money in lump sum at the time of the occurrence of the insurance accident.