Manhattan apartment rents fell as much as 12.3% in June from a year earlier as unemployment curbed demand for new leases, the Real Estate Group of New York said in a report today.

Average rents declined for apartments of all sizes, the brokers said. Rents for one-bedroom units in buildings with doormen had the greatest yearly decline, falling to an average of $3,320 a month. Two-bedrooms in buildings without doormen had the next biggest drop: 11.3% to $3,610 a month.