Sydney Rittenberg, one of the last Americans who stayed in China enthusiastically embracing Maoism and who was eventually imprisoned for his leftist militancy, has been released after 10 years in Chinese detention.

Rittenberg advanced within the Chinese bureaucracy to a point where, for a brief period during the Cultural revolution, he was a member of the three-man committee running Peking Radio. His arrest was due to his reported involvement in a high level conspiracy to topple Premier Chou En-lai.

A brief dispatch from Peking yesterday said taht Rittenberg was released about a month ago, that he was living quietly in a Peking hotel and that he has refused to meet with foreign journalists.

Behind this brief account is a man with an unusual history.

in some ways, Rittenberg's story is similar to those of other American leftists who came to manhood in the '30s and '40s first flirting with Marxism and then moving to the Soviet Union in pursuit of their beliefs.

In other ways, the story is unique. Few Americans have risen as high as Rittenberg apparently did in Chinese Communist society. And few have espoused leftist militancy that made even the Maoists feel uncomfortable.

Rittenberg's grandfather was speaker of the South Carolina Legislature, his fater acting mayor of Charleston, Rittenberg broke from his family, however, leaving school to organize tobacco plantation workers, then public service workers.

During World War II, he underwent training in the first Chinese language training program sponsored by the U.S. Army, became a fluent Chinese speaker, volunteered for relief duty in China after the war's end and moved on to Shanghai. Eventually he went to Peking and to work for the Communists.

At one point, he divorced his American wife and married a Chinese student, with whom he had two children. First he worked as an interpreter for the government, then moved on to the government's key propaganda arm, the All-China Bureau of Broadcasting, to become one of the triumvirate running it.

In the turmoil created by the Culture Revolution, the radio became a battle ground between two rival bands of leftists. Rittenberg sided with the extreme leftists - the so-called "earth faction" - that challenged Chou's power. He was ousted and eventually jailed as an "American spy."

In 1973, Chou referred to Rittenberg as a "very bad person" and he was detained longer than any other American involved in the Cultural Revolution.

The terms of his release are not clear. Rittenberg hs not contacted the U.S. liaison office in Peking, nor has he indicated that he would like to come home for a visit.

His whole stay in China has been a mystery. At one point he became a cause celebre within China, as Red Guard accounts revealed after he fell from grace: "There were people who shouted, 'Defense of Rittenberg is defense of China's Mao revolutionary line. Anyone who opposes Rittenberg opposes the Central Revolutionary group."