The Swedish diplomat was appointed to the post yesterday after four months of haggling between the members of the UN Security Council.

Mr Blix used to be head of the International Atomic Energy Agency (IAEA) and is widely regarded as having had a record of successful co-operation with the Iraqi authorities.

Iraq's foreign ministry under-secretary Nizar Hamdoon said: "The issue is deeper than just naming Blix as head.

"We have major reservations on the resolution of the security council, its conditions and its ambiguity."

Earlier, the council president, Richard Holbrooke, said the decision in favour of Mr Blix had been unanimous.

"We are ... passing his name on to the secretary-general of the United Nations immediately for consideration," Mr Holbrooke said.

Inspection

The IAEA on Tuesday completed a five-day, routine inspection of Iraq's nuclear material to make sure Baghdad's stocks are not being used for military purposes.

The IAEA team leader said Iraq's co-operation had been good.

The inspection, however, is unrelated to the post-Gulf War UN weapons inspections.

It stems from Iraq's obligations to submit to regular inspections under nuclear non-proliferation treaties.

Unwelcome

Mr Annan's first choice for chief, Rolf Ekeus, was the first executive chairman of Unscom, the former UN weapons monitoring commission in Iraq, which was set up after the Gulf war in 1991. He led Unscom until 1997.

His proposed appointment to the new body - The UN Monitoring, Verification and Inspection Commission (Unmovic) - was unwelcome to Iraq.

Unscom withdrew from Iraq in December 1998 on the eve of a US and British bombing campaign.

Finding an acceptable person to head the UN Monitoring, Verification and Inspection Commission (Unmovic) is only the first in a series of steps designed to get UN arms inspectors back into Iraq after a 13-month absence.

Under the new resolution, the UN offers Baghdad the possibility of suspending the sanctions, which were first imposed in August 1990 after Iraq invaded Kuwait.

Iraq has said that it has already destroyed all its weapons of mass destruction and it will not accept a new arms control body.