Ms Sgrena said the US soldiers gave no warning before shooting
Secret agent Nicola Calipari was shot by US forces as he escorted Giuliana Sgrena to Baghdad's airport.
US investigators were reported to have found the troops "not culpable" in a report which Italy has not endorsed.
Italian Prime Minister Silvio Berlusconi refused to comment because he said the inquiry was not complete.
Mr Berlusconi apologised to the Italian parliament for what he called "an unfortunate leak" suggesting that the investigation was completed.
He said contacts were continuing with US officials to try to reach agreement on what happened.
US Defence Secretary Donald Rumsfeld later told reporters: "My latest information is that [the investigators] have not come to a final agreement on a joint report.
"It was done together [with the Italians], intimately, and I think that we'll just have to wait and see what they come out with."
The head of the US Joint Chiefs of Staff Gen Richard Myers said the conclusions of the investigation were expected to be released in Iraq at an unconfirmed date.
'Slap in the face'
Ms Sgrena described the conclusion of the leaked report as a "slap in the face".
DIFFERING ACCOUNTS US military: Car approaches checkpoint at high speed Troops attempt to tell driver to stop with arm signals, lights and warning shots Soldiers shoot into engine Italian government: Italy makes all necessary contacts with the US for safe passage The driver stops immediately when a light flashes 10m away At the same time, shots are fired into car for 10-15 seconds
Accounts in full Profile: Nicola Calipari Papers reject US findings
"All the words said about Calipari would turn into hypocrisy... and Nicola would have been our government's hero, just for one day."
Although Mr Berlusconi has been a staunch US ally in the conflict in Iraq, the war is very unpopular with the Italian people.
A report exonerating the soldiers involved in the shooting could prove inflammatory in Italy, and damaging to Mr Berlusconi.
Correspondents say attempts may be made to agree on a mutually acceptable version before the report is published.
Events unclear
Mr Calipari was hailed as a national hero after he was shot while trying to protect Ms Sgrena from gunfire.
Calipari threw himself over Sgrena when the bullets hit
A US army official said on Monday that they still disagree over the speed at which the vehicle approached the checkpoint where the shooting occurred and how much communication there was between those in the car and the checkpoint guards.
"The United States is ready to release the report but Italy has more questions," the official said.
The US military said the car carrying Mr Calipari was speeding as it approached the temporary checkpoint in western Baghdad.
They said the soldiers used "hand and arm signals, flashing white lights and firing warning shots" to get the driver to stop.
However, Ms Sgrena, who was hurt in the incident, said the car had not been speeding and that there had been no warning before the troops opened fire.
'Feel terrible'
The US military said it had had no knowledge of the rescue mission, dismissing as "absurd" Ms Sgrena's suggestion that her car was deliberately targeted.
Just after the incident, she said it was possible the soldiers had targeted her because Washington opposed the policy of negotiating with kidnappers.
"The soldiers were only complying with the standard operating procedures for those checkpoints, so therefore are not culpable to dereliction of duty [charges]," the US army official told Reuters news agency.
"Everybody feels terrible about it," he said.
The soldiers involved will reportedly face no disciplinary action.
An ongoing US military investigation into the death of the Italian intelligence agent Nicola Calipari cleared the US soldiers charged. A US official speaking anonymously stated, "The soldiers were all complying with the standard operating procedures for those checkpoints and therefore were not culpable of dereliction of duty in following their procedures," according to the Australian Special Broadcasting Service.

The Italian government has rejected the investigation's findings. Prime Minister Silvio Berlusconi later apologised for "an unfortunate leak" that suggested the investigation was completed, and assured paliament that the investigation was not yet over.

Giuliana Sgrena, the journalist of Italian newspaper ''il Manifesto'' who was injured in the shooting, replied, "Unbelievable. They say soldiers followed only their rules of engagement. But if shooting on a machine that is moving, while USA were informed about it, is following rules of engagement, we must ask ourself what kind of rules they are." For Sgrena now "it's important that Italian Magistracy goes on. But all may suppose that its job will not be so easy".

The report was delayed so that disputes might be solved between the two governments. These disputes included disagreements on how fast the car was going as it approached the checkpoint and if US soldiers knew that the car and passengers would be passing through on that day. Italian officials who participated in the investigation are said to have disagreed with its findings.

US soldiers insisted that the car carrying Sgrena and Calipari to the Baghdad airport was traveling at a high speed and failed to heed warnings to stop. The Italian driver of the car denies he was speeding or that soldiers gave a warning. "It's enough to see the car," Sgrena wrote in ''il Manifesto''. "The front windshield is intact, while the side windows and the one behind are shattered."

=== See also ===
* Kidnapped Italian journalist refutes American government claims ''Wikinews'' March 25, 2005