Apartment vacancies hit a 30-year high in the fourth quarter, and rents fell as landlords scrambled to retain existing tenants and attract new ones.

The vacancy rate ended the year at 8%, the highest level since Reis Inc., a New York research firm that tracks vacancies and rents in the top 79 U.S. markets, began its tally in 1980.

Rents fell 3% last year, according to Reis, led by declines in San Jose, Calif., Seattle, San Francisco and other cities that had brisk growth until the recession.

In New York City, the vacancy rate improved by 0.1 percentage point for the second straight quarter, but around 60% of rental buildings dropped their rents in the fourth quarter from the previous quarter. Effective rents -- which include concessions such as one month of free rent -- fell 5.6% in New York last year, the worst since Reis began tracking the data in 1990.

Landlords now must entice tenants to renew leases. "We'll shampoo their carpets. We'll paint accent walls. We'll add Starbucks cards," said Richard Campo, chief executive of Camden Property Trust , a Houston-based real-estate investment trust that owns 63,000 units. He said the first half of 2010 should be "pretty ugly," but was optimistic the sector would pick up later in the year.