NOVATO -- Average advertised rent for apartments in Marin, Napa and Sonoma counties in the third quarter dipped to the lowest level since the end of 2007, yet average North Bay rents have not declined nearly as much as those in Northern California as a whole, according to estimates from Novato-based multifamily property market analyst RealFacts.

The 2.7 percent year-over-year decline in average rent for the three North Bay counties, part of a four-quarter slide, bested the 3.7 percent drop in average rent in the same period nationwide.

While rents dipped in 26 of 33 U.S. markets RealFacts tracked in the third quarter, average occupancy increased in 29 of those markets.

A nearly complete rental-market survey by Larkspur-based NorCal Commercial suggests the third-quarter occupancy rate increasing to 95.1 percent in Sonoma County from mid-2009 and the rate for Marin County slipping to 95.6 percent. Industry average occupancy of more than 95 percent is considered positive.

"Anecdotally, the war stories sound much worse than the reality of what we're finding," said NorCal President Scott Gerber.

Rents in Marin County decreased 3 percent from mid-2009 to the end of the third quarter, according to NorCal. Sonoma County rents slipped 2 percent in that period.