The investigation adjudicated on Tuesday that the crew not only acted correctly but were justified in shooting a shell into the Palestine Hotel because they believed a spotter was coordinating Iraqi fire from there, an official said.
A Ukrainian cameraman for Reuters television, Taras Protsyuk, and a Spaniard working for the Spanish television network Telecinco, Jose Couso, were killed by the blast.
Three other Reuters television journalists were wounded in the attack.
Not yet public
The Central Command's report on its investigation was not immediately made public, but a summary of its findings was sent to the governments of Spain and Ukraine, said the official.
"The report appears to confirm exactly what was initially reported in April," said the official. "The rules of engagement were not violated."
US forces picked up transmissions on a captured Iraqi radio of someone in the area directing Iraqi fire, a second official said.
The tank targeted the Palestine Hotel after seeing someone with binoculars on an upper floor acting "in a manner consistent with that of a spotter," the official said.
But in the immediate aftermath of the attack, US military officials said the tank was returning hostile fire from the hotel. Journalists at the hotel disputed that account.
Images captured by the French television network France 3 showed the turret of an Abrams tank on the west side of the Tigris river turn toward the Palestine Hotel 300 metres away on the opposite bank open fire.
In Kiev, the Ukrainian foreign ministry said it had been informed of the investigation's findings.
"According to the American side ... the shot was fired in self-defense and in complete conformity with the rules of combat," said ministry spokesman Markian Loubkivski, citing the US report.
But a separate investigation by the Committee to Protect Journalists, a watchdog group, concluded in May that the attack was avoidable.
Pentagon officials and military commanders on the ground in Baghdad knew the hotel was full of journalists, but failed to warn the tank's commander, the committee said.