Japanese land prices may drop for the next 15 years, according to the president of Sanyu Appraisal Corp., a real estate appraisal firm.

The real estate market is headed for a depression that's worse than after the asset bubble collapsed in 1990, Akiyoshi Inoue, the Tokyo-based firm's president, said Wednesday, adding land prices will fall for at least the next 15 years.

Land prices at 85 percent of monitored sites fell in the three months that ended Sept. 30, according to a Land Ministry survey released Nov. 21, a sign that a two-year-old recovery in land prices from a 15-year slump has run its course.

Real estate values are falling as the global credit crisis and recession are prompting banks to reduce lending and companies to cut back on investment.

Inoue said one ominous sign is the recent drop in land prices in the prime business districts of Marunouchi and Otemachi. The land ministry survey showed that land prices in Otemachi fell 3 percent in the three-month period to Sept. 30.

Real estate prices in Marunouchi and Otemachi will likely continue to decline, and overall rents will probably fall, too, Inoue said.