The number of new condominiums put on sale in the Tokyo metropolitan area in August jumped 42.1 percent over the previous year to 4,715, a record high for the month, the Real Estate Economic Institute said Thursday.

The private institute, which began compiling data in 1973, said condo suppliers increased their offerings in August ahead of this fall's massive surge in supply.

In particular, the supply of high-rise condos soared 92.8 percent to 347 units.

The ratio of sales contracts signed to new supplies in August came to 78.5 percent, up 0.8 percentage point from a year earlier and up 3.5 points on a month-to-month basis. It was also well above the boom-or-bust line of 70 percent.

The average per-unit price dropped 2 percent in August from a year earlier to 37.92 million yen, while the average price per square meter stood at 495,000 yen, also down 2 percent.

The institute predicted some 7,500 new condos will be put on the market in the metropolitan area in September.

It said 1,512 new condos were offered in the Kinki region, centering on Osaka, in August, up 20.8 percent over a year earlier.

The ratio of sales contracts to new suppliers came to 74.1 percent, down 3.9 percentage points from a year earlier, but up 0.7 point over the previous month.