The office vacancy rate in five central Tokyo wards hit a record high 8.94 percent at the end of May, rising 0.12 percentage point from a month earlier, office broker Miki Shoji Co. said Thursday.

The vacancy rate in Chiyoda, Chuo, Minato, Shinjuku and Shibuya wards rose for the ninth straight month, reaching its highest level since the company began compiling data in 1989. It said firms are consolidating or reducing offices to cut costs.

The average rent for offices in the area dropped 12.45 percent from the same month last year, Miki Shoji said.