By Jon Leyne BBC State Department correspondent

The US waived legislation so foreign companies could help rebuild Iraq

The United States has assured foreign companies that they will be allowed to bid for contracts for the reconstruction of Iraq after the war is over.

There has been concern in Britain and elsewhere after only US companies were allowed to bid for the first raft of contracts, worth nearly $1bn.

But there are still deep differences over how to go about rebuilding Iraq, some of which will be discussed by UK Prime Minister Tony Blair when he visits Washington this week.

Already big differences are emerging over what happens after the war in Iraq, with concern emerging that the US is trying to corner the reconstruction work.

But the head of the US aid programme, Andrew Natsios, insisted that Washington was going to let foreign companies into Iraq.

He said he had been in talks on the issue with two UK Foreign Office ministers and had assured them that the US Government had waived legislation in order to let foreign companies share the work.

UK influence

Nonetheless tension remains over the shape of a future Iraqi government - differences between the US and the United Nations, but also within the administration itself.

The Pentagon is believed to want a swift handover to a group of hand-picked Iraqis.

The US State Department, the UN and Britain want a UN-sponsored conference to appoint an interim administration.

France and Russia are threatening to block the whole process.