Japan's Seibu Holdings is considering selling a high-end office building in central Tokyo for at least ¥300 billion, people familiar with the matter have said, in what would be one of the country's biggest property deals on record.

The potential sale of the 36-story Tokyo Garden Terrace Kioicho office and hotel complex is aimed at helping Seibu free up its balance sheet, something Japanese firms are increasingly looking to do amid pressure from shareholders and regulators for better use of capital.

A deal by the 111-year-old property and railway company would also come as global demand for Japanese commercial real estate remains robust, given attractive terms including low borrowing costs and stable rents.