The average cost of a new condominium in the greater Tokyo area has fallen for the third straight month. But prices remain high overall on the back of higher construction costs.

The Real Estate Economic Institute says the average price of condos in Tokyo, plus neighboring Kanagawa, Saitama and Chiba prefectures was around 474,000 dollars in May. That's down 7.2 percent in yen terms from a year ago.

The average cost in the capital's central 23 wards was around 654,000 dollars, marking a 10 percent decline. That's in reaction to last year's trend, when more luxury units were on the market.

But the institute says prices in other places in Tokyo went up, amid rising construction costs. The average for Tokyo, excluding the 23 wards, saw a nearly 30 percent increase. The three prefectures of Kanagawa, Saitama and Chiba all showed increases as well.