The number of Bay Area homeowners facing foreclosure rose to the highest level in more than seven years in the third quarter, while foreclosure activity statewide was higher than anytime in more than four years, a real estate information firm reported Wednesday. Despite the increases, foreclosure activity is still below average levels regionally and statewide, experts noted. Owners who receive ``default notices'' -- the first step in the foreclosure process -- are ``still a small percentage of all mortgage loans, and foreclosures are a fraction of that,'' said Delores Conway, director of the Casden Forecast at the University of Southern California's Lusk Center for Real Estate. ``So we have to keep that in perspective.''