ISLAMABAD, Pakistan - President Pervez Musharraf's chosen candidate defeated a pro-Taliban cleric in a parliamentary vote for prime minister yesterday, garnering just enough votes to ensure a smooth transition of power and Pakistan's continued cooperation with the United States in its efforts against terror.

Zafarullah Khan Jamali, 58, a veteran politician from the southwestern province of Baluchistan, who served as a minister under a previous military government, got 172 votes, barely the majority he needs to form a government. Musharraf, the army chief of staff who took over in a coup three years ago, will ceremonially relinquish executive powers to the new prime minister at a ceremony tomorrow.

Jamali is unlikely to wield those powers on his own. His role as standard-bearer of the pro-Musharraf party, the Pakistan Muslim League-Quaid, will be to allow Musharraf and the army to maintain a strong grip on power. That will be welcomed in Washington, where Bush administration officials have watched with unease the unexpected success at the polls of an alliance of hard-line Islamic parties.

But Jamali faces strong opposition. Newspaper commentators here predicted that his slim parliamentary majority would give his coalition little room to maneuver. And legislators suggested that the coalition would not be strong enough to survive its five-year term.

"His majority is wafer-thin," said Shah Mahmood Quereshi of Benazir Bhutto's Pakistan People's Party, who finished third in the legislative vote for prime minister. If Jamali tried to push through Musharraf's agenda without due consultation with parliament, Quereshi said, he would be rapidly brought down by a vote of no confidence. By law, the new government has to win a vote of confidence within three months of taking office.

The Islamic alliance candidate for prime minister was Maulana Fazl-ur-Rahman, a supporter of the former Taliban regime in Afghanistan and vocal opponent of the U.S. presence in the region. With 60 seats, the alliance was for a while in discussions with the pro-Musharraf party to form a coalition, but it refused to give up Rahman as its candidate.

In the end, Jamali managed to assemble enough votes for a majority without having to make a deal with Rahman or the other large opposition group, the Pakistan People's Party. Rahman finished second to Jamali in yesterday's ballot, garnering 86 votes. Quereshi followed with 70.