In Century 21, residential sales will be shot into cyberspace, the world's brokerage giant decide. (Century 21 Real Estate Corp.)(Real Estate Quarterly)

On Aug. 1, the owners of Hartford Properties, the largest woman-owned residential real estate agency in San Francisco with $75 million in home sales last year, aligned itself with Century 21 Real Estate Corp. While its decision to join forces with a national real estate firm was not unusual, the same could not be said for its choice of partner.

The bright yellow Century 21 for sale signs are an icon of middle America, but the world's largest residential real estate firm :is far less dominant in the Bay Area. That's especially true in San Francisco, where its yellow-jacketed agents barely register as a ripple in the flood of this cites high-priced real estate.

Yet Hartford owners Linda Service and Helen Parduhn Marshall passed over better established San Francisco companies like Prudential Jon Douglas and Pacific Union to align their 35 agents with Century 21, becoming one of only five such outlets in the entire city and the first to stake out a territory in the neighborhoods of Noe Valley, the Castro and Upper Market. Their choice illustrates the change going on at Century 21 under its new management.

"I believe there is a revolution going on in the residential real estate …