Office rents nationwide declined 8.5 percent in the third quarter of 2009 compared to the previous year, according to Reis, Inc., a real estate research firm. At the same time, office vacancies rose. At the end of the third quarter, tenants were leasing some 19.6 million square feet less than at the beginning, according to Reis.

For the first three quarters of 2009, the net reduction in rented office space was 64.2 million square feet, the largest decline since records began to be kept in 1980. The vacancy rate was 16.5%, the highest since 2004. Of 79 metropolitan areas tracked by Reis, vacancies rose in 72 of them in the third quarter, and rents declined in 68 of them. Of course, no one can predict the future, but with rents at such low levels it might be a good time for tenants to renegotiate a lease and lock in rates for a longer term.