SAN JOSE, Calif. (AP) _ Joseph B. Ridder, publisher of the San Jose Mercury News for 25 years and a member of one of the nation's major newspaper families, died in a Honolulu hospital at age 68, the newspaper reported today.

Ridder, who died Monday, had been hospitalized with complications from emphysema, said brother Daniel Ridder, chairman of the Long Beach Press- Telegram.

Ridder was publisher of the Mercury News from 1952 to 1977, during which the city's population grew from about 100,000 to over 600,000 and circulation of the Mercury and News, then separate morning and afternoon papers, grew from 73,000 to 211,000.

He was succeeded by a nephew, P. Anthony Ridder, now president of Knight- Ridder Inc., parent company of the Mercury News and several other newspapers, including The Philadelphia Inquirer, The Miami Herald, The Journal of Commerce and the Detroit Free Press.

Ridder was born into one of the nation's major newspaper families in New York City. He attended Canary College in Virginia.

During World War II, he was promotion director of the Duluth (Minn.) Herald and News Tribune and general manager of the St. Paul Pioneer Press and Dispatch.

The family acquired the San Jose newspaper in 1952. Ridder, then 32, was named publisher.

Survivors include two brothers. Funeral services were scheduled for Thursday at Ridder's home in Honolulu.