NEW YORK - Investigators probing the U.N. oil-for-food program in Iraq will criticize U.N. Secretary-General Kofi Annan, his son, and the Swiss company that employed him, but will not accuse the U.N. chief of corruption, officials said.

The report to be released today will fault Annan for failing to take aggressive action to deal with possible conflict of interest in the awarding of a U.N. oil-for-food contract to Cotecna Inspection S.A., which employed his son, Kojo, in Africa, the officials said.

It will also be highly critical of Kojo Annan for concealing information about his dealings with Cotecna and for deceiving his father, and it will blame the Swiss firm for failing to make information public about the secretary-general's son, the officials said on condition of anonymity.

The report will be the second issued by the team of investigators led by former U.S. Federal Reserve chairman Paul Volcker. It comes a week after Annan called for the biggest overhaul of the United Nations in its 60-year history. It also coincides with allegations of sex abuse by U.N. peacekeepers and of sexual harassment and mismanagement by senior U.N. staff.

Volcker's committee of inquiry will also censure Annan for failing to detect shortcomings in the U.N. bureaucracy that allowed problems in the $64 billion humanitarian aid program to continue until it was wrapped up after the U.S.-led war in Iraq, the officials said.

While the new report will fault the secretary-general's overall management of the oil-for-food program, it will support statements by his chief of staff and spokesman as recently as Monday that "the secretary-general expects to be cleared of any wrongdoing."

As one official said, "He's not going to be implicated in corruption in any form whatsoever."

For the secretary-general, this will almost certainly be the most important finding.

The oil-for-food program was the largest U.N. humanitarian aid operation, running from 1996-2003. Saddam Hussein's government was allowed to sell limited amounts - and eventually unlimited amounts - of oil in exchange for humanitarian goods as an exemption from U.N. sanctions imposed after Iraq's 1990 invasion of Kuwait.

In a bid to curry favor and end sanctions, Saddam allegedly gave former government officials, activists, journalists and U.N. officials vouchers for Iraqi oil that could then be resold at a profit. U.S. congressional investigators say Saddam's regime may have illegally made more than $21 billion.