An investigation of the U.N. war crimes tribunal for Rwanda has found widespread mismanagement, waste and incompetence but did not turn up evidence of corruption, the United Nations reported today.

The findings confront Secretary General Kofi Annan, who took office Jan. 1 promising broad reform, with some sensitive decisions.

Critics in the U.S. Congress believe the world body has an inept bureaucracy badly in need of purging. But African governments resent suggestions that the largely African staff of the Rwanda tribunal is the place to start. They are expected to put pressure on Annan, a native of Ghana, not to dismiss personnel, according to diplomats and other observers here.

A 50-page report by Karl Paschke, the United Nations' equivalent of an inspector general, charged that the tribunal administration functioned chaotically during most of the two years since it was established. The court was created to try persons implicated in the massacres of more than half a million Tutsis and moderate Hutus during Rwanda's 1994 tribal strife.

Unless the situation is corrected quickly, "the Rwandese will be right to suspect that justice delayed is justice denied," said Paschke, undersecretary general for internal oversight.

He recommended discharging the tribunal's deputy prosecutor, Honore Rakotomanana of Madagascar, but did not call for ousting the chief administrator, Andronico Adede of Kenya. Annan has summoned both Adede and Rakotomanana to meet here with him and the chief prosecutor, Louise Arbor of Canada, on Feb. 21 and will decide afterward what actions to take, U.N. spokesman Fred Eckhard said.

Paschke's report did not fault the tribunal's judges but focused hard on its administrators. Several months ago, many of them became the target of persistent allegations that they gave jobs to unqualified friends, relatives and lovers, discriminated against non-Africans and misused tribunal funds and equipment.

At a news conference today, Paschke noted that Annan and his predecessor, Boutros Boutros-Ghali of Egypt, had intervened when the allegations first surfaced and had corrected many deficiencies. He also insisted in the face of persistent questioning that his investigators "had not confirmed allegations of corrupt practices like racism, nepotism and misappropriation of funds."

However, he added, the tribunal has been an administrative nightmare since its establishment by the Security Council in 1995. Its headquarters in Arusha, Tanzania, is headed by Andronico, and Rakotomanana leads a prosecutors office in the Rwandan capital of Kigali. The tribunal has indicted 21 people, and is conducting its first trial against Jean-Paul Akayesu, a former Rwandan mayor charged with inciting the public to murder.

The report said that part of the trouble resulted from the failure of U.N. headquarters in New York to assign adequate, qualified staff to the two trial locations. Judges in Arusha and Kigali have complained publicly that administrators assigned them unqualified assistants, monitored their phone calls and obstructed their work through bureaucratic interference.

Slipshod administration caused several staffers to go for months without receiving their salaries, while running up thousands of dollars in advances. One employee failed to report that he had been paid twice and owes the United Nations more than $34,000. Yet, the report said, the U.N. personnel department approved extension of his contract until mid-1997.

In perhaps the most egregious incident, a plane chartered at a cost of $27,000 went to pick up suspects detained in a West African country, but had to return empty because no agreement had been reached in advance for that country to turn over the prisoners.