ISLAMABAD, PAKISTAN, NOV. 6 -- Nawaz Sharif, a conservative industrialist and Benazir Bhutto's chief rival, was sworn in today as prime minister of Pakistan's fifth freely elected government in 43 years.

Sharif, 41, was elected by the National Assembly after a brief walkout by supporters of ousted prime minister Bhutto, who demanded a secret ballot. Hours later, President Ghulam Ishaq Khan administered the oath of office to Sharif in a 10-minute ceremony attended by 600 guests, including politicians, military leaders and bureaucrats.

Sharif, whose Islamic Democratic Alliance soundly defeated Bhutto in the Oct. 24 election, called for reconciliation, saying, "the government and opposition should join hands to help the country's poor." He referred to the majority of Pakistan's 110 million people, most of whom are illiterate, landless laborers earning less than $400 a year.

Earlier, in an address to the assembly, Bhutto sharply criticized the army-backed caretaker government that succeeded her after the president dismissed her government and called elections Aug. 6. "I hope the new administration will depart from the policy of repression, persecution and discrimination launched by the caretaker government," she said.

Sharif began his political career in the 1980s as a provincial-level appointee of Pakistan's military ruler, Gen. Mohammed Zia ul-Haq. For last month's elections, Sharif formed the Islamic Democratic Alliance from a conservative-dominated group of parties that are united mostly in their opposition to Bhutto.