Amintore Fanfani, 91, a six-time Italian premier and a former head of the U.N. General Assembly, died at his home here Nov. 20. Earlier that day, he had returned home from a Rome hospital where he had been treated for the flu and a heart ailment.

Twice leader of the Christian Democrats, holder of a succession of ministries and a senator for life, Mr. Fanfani's high-profile involvement in Italian politics covered half a century. The diminutive statesman with piercing black eyes held almost every important political office in Italy except the presidency--a post that eluded him twice.

Mr. Fanfani, who was born in Tuscany, was an economics graduate of the Catholic University in Milan.

He taught economics and history at the university from 1936 to 1955 and at the University of Rome from 1955 to 1983. It was from this profession that he earned one of his many political nicknames--the Professor.

His political life started at the end of World War II. In 1946, Alcide De Gasperi invited him to Rome to become involved in the nascent Christian Democrats, the party that would lead Italy until the 1990s.

In De Gasperi's government, Mr. Fanfani began to make his name under the post of labor minister when he pushed through laws for workers' housing. In the early 1950s, he served as agriculture minister, interior minister and foreign minister, introducing liberal reforms.

His first government, in 1954, and his last, in 1987, were two of the shortest on record--12 days and 10 days, respectively. It was during his fourth term as prime minister, in 1962 and 1963, that Mr. Fanfani led the Christian Democrats into a governing alliance with the Socialists that was to pave the way for a succession of governments that shaped Italian politics.

Only De Gasperi, who headed eight successive governments in the immediate postwar period, and seven-time premier Giulio Andreotti served as prime minister more times.

Mr. Fanfani's last proper term as prime minister ended in 1983, when his coalition resigned amid internal dissent.

But he returned to the prime minister's office in 1987 after a worsening dispute between the now-disgraced and defunct Christian Democrats and the Socialists brought down the government of Socialist prime minister Bettino Craxi.

His caretaker government deliberately lost a confidence vote after just 10 days in office, triggering a general election.

As prime minister, Mr. Fanfani achieved his greatest successes in foreign affairs. His appointment as president of the U.N. General Assembly in 1965 added to his international standing.

Between 1965 and 1968, he worked to improve relations between East and West, proposing that Mao Zedong's China be admitted into the United Nations and meeting with a delegation from Hanoi to push the Vietnam peace effort.

The low point in Mr. Fanfani's career came in 1974 and 1975, when he campaigned vigorously against the legalization of divorce, declaring that it could lead to lesbian marriages and affairs "in which your wife could run away with your maid." His crusade failed, and Italians approved divorce in a referendum.

In 1975, Mr. Fanfani was forced to resign as Christian Democrat secretary after the party's poor showing in regional elections.

But he fought his way back with undiminished energy, regroomed his image and rose to the leadership of the Senate in 1976, when he began to moderate his once trenchant right-wing views and cultivate the image of a senior statesman.

Colleagues described his governing style as firm, bordering on the authoritarian, and arrogant and paternalistic.

Mr. Fanfani often spoke of his friendship with John F. Kennedy, whom he first met in 1956 in Chicago.

He cited with pride a story told him by Kennedy's colleagues--that it was Mr. Fanfani's book "Catholicism, Protestantism and Capitalism" that persuaded Kennedy to dedicate his life to politics.

Over the years, he had a number of works published on politics, religion and art. His most recent publications included "Constitution, Parliament and Government" in 1982.

Mr. Fanfani, a proficient soccer player in his youth, once told journalists the worst aspect of a government crisis was that it interfered with his favorite Sunday pastime--watching soccer.

His other hobbies were abstract painting, for which he earned high praise, collecting miniature Madonnas and cooking the spicy savories and candied fruit tarts of his mother's native Calabria region.

His first wife, Bianca Rosa Provaroli, died in 1968.

Survivors include his wife, the former Maria Pia Tavazzani, a writer and widow whom he married in 1975 and who lives in Rome; and seven children from his first marriage.