State-owned China Construction Bank Corp has become the first Chinese lender to buy a single office building in Seoul, the South Korean capital, in a deal worth 300 million yuan ($48.5 million), the Seoul office of the bank has confirmed.

The deal to acquire the 12-story Tongyang Life Insurance building was agreed in October and marks the first major expansion in the city by a leading Chinese organization.

Located on an avenue called Euljiro in downtown Seoul, the building is near the main offices of many Korean multinational corporations and financial institutions.

China Construction Bank, one of the country's four major State-owned banks, said it plans to relocate its current Seoul office from the Seoul Finance Center building in Gwanghwamun to the site, and that the tower will become the base of further retail banking expansion across the country. It will use some floors as office space and lease out the rest. The purchase is expected to be completed by the end of December.

China Construction Bank's Seoul office said it had bought the building at an opportune time during a weakening in South Korea's real estate market.

It also said the owner of the building had been looking to liquidate some of its assets, and that it was optimistic about the investment prospect of the building, based on its prime location.

Chinese outbound investment in commercial property totaled $33.7 billion between 2008 and June 2014, growing more than 200-fold in that time, according to a report by Cushman & Wakefield, a global private commercial real estate services firm.

Last week, Bank of China Group Investment Ltd, an affiliate of State-owned lender Bank of China Ltd, agreed to buy office space in a commercial tower in Bryant Park, New York City.

In October, China's Anbang Insurance Group Co bought the landmark Waldorf Astoria hotel in Manhattan from Hilton Worldwide Holdings Inc.

Lu Ming, Cushman's Beijing-based research manager, said part of the reason for China Construction Bank's acquisition in Seoul is optimism over the stable South Korean economy and an expected rise in yuan-related business in the country.

"Construction Bank is going to grow its presence and influence in South Korea, as China and South Korea have reached a major free-trade agreement and will start direct trading between the yuan and the South Korean won," Lu said.

"It will provide related financial services locally and process yuan business overseas following the outbound movements of other industries."