Buildings in central Seoul / gettyimagesbank

The average vacancy rate for offices in Seoul reached 2.9 percent in the third quarter, showing an increase of 0.3 percentage points from the previous quarter's 2.6 percent, according to data released Monday by commercial property broker Rsquare. This marks the third consecutive quarter of rising vacancy rates.

Although the figure remains low and is still below the natural vacancy rate, it represents a significant increase compared to last year's 1.7 percent.

Rising vacancy rates are attributed to large tenants actively seeking new office spaces as they look to cut costs by moving away from their existing locations.

For instance, SK Square's subsidiary, online market 11st Street, has decided to relocate from its current location in Seoul Square in front of Seoul Station to a building in Gwangmyeong, Gyeonggi Province.

Shinsegae Group's e-commerce platform, SSG.com, which was located in Seoul's affluent Gangnam District, will be relocating this quarter to southwest Seoul's Yeongdeungpo District.

Similarly, Coupang, which currently has offices in Gangnam District and Songpa District, has also decided to move its headquarters to eastern Seoul's Gwangjin District.

The Gwanghwamun and Seoul City Hall areas appeared to have been the most significantly affected by the trend of large corporations relocating their offices. In these areas, the office vacancy rate for the third quarter was 3.1 percent, which was a 0.5 percentage point increase from the previous quarter.

"The shift in leasing strategies among tenants planning to relocate their headquarters for the purpose of improving operational efficiency is expected to significantly impact the Korean office leasing market, necessitating close monitoring of the situation," an Rsquare official said.