The Supreme Court of Pakistan today rejected former Prime Minister Zulfiqar Ali Bhutto's appeal of his death sentence in a murder case.

Unless the court agrees to review its finding or President Mohammed Zia ul-Haq gives clemency to Bhutto, the man who led this country from 1971 to 1977 will be hanged. Zia has said he will abide by the decision of the court.

Today's decision is expected to spark widespread unrest by Bhutto's supporters, a factor the government apparently had in mind over the past several days as it rounded up hundreds of members of Bhutto's Pakistan People's Party and placed others, including his wife, under house arrest.

With Iran in turmoil to the west and with reports of violence building in Afghanistan to the north, extreme civil unrest in Pakistan would mean a wide swath from the Middle East to India would be embroiled in chaos and uncertainty.

Tension in the courtroom was high today before the seven judges filed in to announce their verdict. A heavy contingent of armed troops guarded the court and visitors were subjected to two separate searches.

Nevertheless, a young soldier appeared briefly at the back of the court and shouted: "If Bhutto is punished, I will not leave one general."

Bhutto and four codefendants were convicted by the Lahore High Court of conspiring in 1974 to murder Ahmed Raza Kasuri, a former ally of Bhutto. Kasuri survived the ambush but his father, riding in the same auto, was killed.

The specter of Bhutto facing the hangman's noose is a sharp contrast to the image of the dapper, Oxford-and Berkeley-educated politician who played the game of power politics with such relish.

Political leaders throughout the world have urged the Pakistani leadership to show clemency in its dealings with Bhutto, but Zia has said consistently he would follow the decision of the court.

It had been thought earlier that the sentence would be carried out swiftly if the court upheld Bhutto's conviction, but that now appears unlikely.

Under a 1965 Supreme Court rule, there is a 30-day period available to the defense to file an application asking the judges to review their findings.

If the court stands by its judgment, seven days are allotted to file petitions to the president seeking clemency, an act Bhutto has forbidden his family to take.

Bhutto's counsel, Yahya Bakhtiar, immediately asked the court for a stay of execution to allow him to study the judgment and put in an appeal for a review.

Zia was army chief when the military moved against Bhutto in a coup 19 months ago after Pakistan was enmeshed in violence and unrest involving charges that Bhutto had rigged an election.

Even then, there were few who were neutral about the flamboyant 51-year-old Bhutto. Members of the People's Party, his supporters in his native province of Sind and others in rural areas stood by the former premier, even as he was in the prisoner's dock.

Equally as intense in their opposition to Bhutto were the many who suffered under his various reform policies or under the heel of the federal security force or police.

The divisions remain and a government official said yesterday that 455 workers from Bhutto's party had been rounded up in major cities in the past few days under a preventive detention law to preserve public order. About 1,000 higher-ranking Bhutto political workers are reported to have been in custody since similar police sweeps last year.

All colleges and universities were ordered closed until further notice in populous Punjab Province and the adjoining Northwest Frontier Province. Pro-Bhutto students in both of the two northern provinces of Pakistan had threatened demonstrations if Bhutto is to be hanged.

Bhutto's Iranian-born wife, Nusrat, was placed under house arrest today, according to sources close to her family. They said she was served with a notice detaining her for a month, which means she was not able to attend the Supreme Court hearing.

Mrs. Bhutto was freed less than two months ago, after spending more than a year in and out of house arrest under martial law. A high court then ruled that her detention was illegal.

Their daughter, Benazir, has been under house arrest for most of the last 10 months, for making antigovernment speeches.

Bhutto continues to enjoy much support among the masses in this nation of 75 million.