Worth a million? Many are in King County

With 68,390 millionaire households, King County has the tenth-largest number of millionaires of any county in the United States, according to a survey released Tuesday by a London market research firm.

King County has 33 percent of the state's millionaire households and 1 percent of those in the nation, according to the study by TNS.

The study defined a millionaire household as one with a $1 million net worth, excluding primary residence.

TNS said the number of U.S. millionaire households had risen to a record high of 9.3 million as of mid-2006. That's an increase of 5 percent from the previous year.

Los Angeles County leads the nation with 268,136 millionaire households -- 3 percent of all such households in the United States.

Following that are Cook County, Ill., with 171,118 households; Orange County, Calif., with 116,157; Maricopa County, Ariz., with 113,414; San Diego County, with 102,138; Harris County, Texas, with 99,504; Nassau County, N.Y., with 79,704; Santa Clara County, Calif., with 74,824; and Palm Beach County, Fla., with 71,221.