The move comes as Nuri al-Maliki, the Iraqi prime minister, pressed the US for Blackwater's early exit despite a six-month deadline he had set earlier.
Anne Tyrrell, a Blackwater spokeswoman, said: "We will follow the lead of our client. If they want us to stay, we will stay. If they want us to leave, we will do so."
"The actions of these contractors will ultimately reflect on coalition forces in general"
Kyle, Fremont, US
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The final decision on Blackwater's fate remains with Condoleezza Rice, the US secretary of state, who has yet to consider the outcome of the department's findings.
The panel reviewed rules of engagement for department escorts and whether anything unique to Blackwater's training, operations and corporate culture made judgment errors or civilian deaths more likely.
The panel is expected to submit the report, which also covers two other private security firms in Iraq, to Rice as early as Friday.
Also on Wednesday, George Bush, the US president, evaded a question as to whether he was satisfied with the performance of security contractors in Iraq.
"I will be anxious to see the analysis of their performance," he said. "There's a lot of studying going on, both inside Iraq and out, as to whether or not people violated rules of engagement."
He said he appreciated Blackwater's valuable service and the sacrifice made by its employees in the service of protecting people's lives.
"If they want us to stay, we will stay. If they want us to leave, we will do so"
Anne Tyrrell, Blackwater spokeswoman
In the September 16 shooting, Iraqi officials said Blackwater guards opened fire without provocation in Baghdad's Nisoor Square, killing 17 citizens.
Al-Maliki demanded the company be expelled from Iraq within six months and pay $8m in compensation for each dead person.
Blackwater is the biggest security company in the war zone with more guards and equipment than both its biggest competitors combined.
The three contractors share a $571m annual contract to protect diplomats and others in Iraq, Afghanistan, Israel and other countries. The Iraq portion accounts for about $520m.