June 13 (Bloomberg) -- Alvaro Cunhal, leader of the Portuguese Communist Party for more than three decades, died this morning at the age of 91, the party said on its Web site.

A leader of the underground resistance to the dictatorship of Antonio de Oliveira Salazar, who ruled Portugal for almost half a century, Cunhal spent 11 years in prison before escaping and fleeing the country in 1960. The party didn't give a cause of Cunhal's death.

After the dictatorship fell in 1974, he returned to Portugal and helped the party gain influence in the military government that followed. With the start of free elections in 1975, Cunhal's Communists were never able to manage better than a third-place finish.

Cunhal, who visited the Soviet Union several times starting in the 1930s, expressed admiration for Joseph Stalin's leadership. That helped fuel criticisms that the Portuguese Communist Party was undemocratic in its ideology and internal politics, with periodic expulsions of dissidents.

The Communists took 7.5 percent of the vote in this year's parliamentary elections. They last exceeded the 10 percent mark in 1987.

Cunhal, born in Coimbra, central Portugal, in 1913, joined the Communist Party while studying law at the University of Lisbon. He headed the party from 1961 until 1992.

While in prison for his political activity, he was taken from jail so he could defend his dissertation before a jury of professors. The jury, which approved the dissertation calling for legalization of abortion, included Marcelo Caetano, who went on to become prime minister in the final years of the dictatorship.

Cunhal wrote several novels under a pseudonym, one of which was made into a television mini-series broadcast this year, depicting the Communists' efforts to organize rural workers in the 1940s. While in jail in the 1950s he translated Shakespeare's ``King Lear'' into Portuguese.

To contact the reporter on this story: Jim Silver in Lisbon at jsilver@bloomberg.net

Last Updated: June 13, 2005 04:43 EDT