UNITED NATIONS — The new Pakistani premier, Yousaf Raza Gilani, sought yesterday to restore his country’s image as a functioning democracy, even as he asked Secretary-General Ban to consider a U.N. probe into the assassination of Benazir Bhutto, bypassing Pakistan’s own law enforcement institutions.

Mr. Gilani made the request yesterday after Mr. Ban called to congratulate him on his appointment, a U.N. spokeswoman, Michele Montas, said. The prime minister, a member of Bhutto’s Pakistan People’s Party, said the Pakistani parliament would consider a resolution calling for a U.N. investigation, Ms. Montas told reporters.

In one of his first acts as premier, Mr. Gilani on Monday ordered the release of Chief Justice Iftikhar Chaudhry and nine other judges whom President Musharraf placed under house arrest five months ago. The removal of the judges was denounced in Pakistan and abroad as an assault on the democratic institutions of the country, and PPP leaders had promised to reinstate them.

A former Pakistani prime minister and opposition coalition member, Nawaz Sharif of the Pakistan Muslim League-N, warned America that Pakistan would review relations between the two countries, particularly the war on terror. “Pakistan cannot be made a killing field for the interests of others,” Mr. Sharif said Tuesday after meeting with Deputy Secretary of State John Negroponte and Assistant Secretary of State Richard Boucher.

Mr. Gilani’s request for an outside investigation may have been ill-advised, several U.N. diplomats said yesterday. Although members of the opposition have long floated the idea of an international probe into the December killing of Bhutto, a former prime minister, it is an unusual act for a leader, one diplomat who requested anonymity said.

Another diplomat said Mr. Gilani may have not consulted with Pakistan’s foreign office and law enforcement before making the request, which could raise several thorny issues for the country. Ms. Montas said yesterday that before the United Nations can launch an investigation, a government must first officially request it, and then the U.N. Security Council must order it.

The council put together a team to probe the February 2005 assassination of a former Lebanese prime minister, Rafik Hariri, but the results of that investigation will be delivered at an international tribunal that is not yet functioning.