The largest vacancy increases have been in the Airport West submarket and in Miami Beach, where last year's dotcom craze resulted in a construction boom and the largest office inventory in Miami-Dade county.

But the Brickell and Downtown submarkets, where class A lease rates are running as high as $38 per sf, have maintained high levels of occupancy. Overall gross lease rates are averaging $21.72 per sf.

According to CB Richard Ellis first vice president Mike Klotz, the third quarter statistics mirror those of the second quarter and are a continuation of a softening trend that began in March, rather than a result of the terrorist attacks of Sept. 11. "I haven't had anyone tell me that Sept. 11 has affected their plans," Klotz tells GlobeSt.com.