Apartment Investment & Management Co. (AIV) swung to a loss in the third quarter on a drop in both occupancy rates and average rents, as the apartment manager saw a key profitability metric fall.

Rising unemployment has increased the pressure on multi-family dwellings. Most developers have halted new projects. Aimco is focusing on retaining residents and keeping costs down, but recently it has seen occupancy rates fall and costs rise.

The real-estate investment trust posted a loss of $27.5 million, or 35 cents a share, compared with a year-earlier profit of $173.7 million, or $1.35 a share. The results included income from discontinued operations of 29 cents and 95 cents, respectively. Revenue decreased 7.3% to $319.3 million while same-store revenue was down 2.9%.

A survey of analysts by Thomson Reuters projected a 35-cent loss on revenue of $313 million.

Funds from operations, an important measurement of profitability for REITs, fell to 25 cents a share from 41 cents. In July, the company projected 36 cents to 42 cents.

Average rents dropped 3.5% and occupancy fell to 94.8% from 95% a year ago.

Aimco narrowed its 2009 FFO forecast, projecting 32 cents to 40 cents a share for the fourth quarter.

Shares in Aimco closed Thursday at $13.18 and weren't active premarket. The stock, which has more than doubled from an all-time low in March, is up 14% so far this year.

-By Joan E. Solsman, Dow Jones Newswires; 212-416-2291; joan.solsman@dowjones.com