Al-Zarqawi and three others received the death penalty in absentia. But the plot's alleged mastermind, Azmi al-Jayousi, and four co-defendants were in the courtroom when the judge handed down the sentence for the 2004 plot, which security officials foiled before it could be carried out.
"Bin Laden's organization is rising and we will be back!" the defendants shouted after the sentencing, referring to the al Qaeda terror network led by Osama bin Laden.
The court sentenced two of the 13 defendants to prison terms of between one and three years, and acquitted another two defendants.
After the sentencing, the convicted men turned on one of the acquitted, a Syrian, and accused him of being an informer. They threatened to kill him, but they did not attack him in the dock.
The 13 men — Jordanian, Syrian and Palestinians — were charged with conspiring to attack various sites in Jordan by setting off a cloud of toxic chemicals that would have killed thousands of people, according to prosecution estimates.
The prosecution told the court that al-Zarqawi sent more than $118,000 to buy two vehicles which the plotters were to use in the attack. Suicide bombers were to drive the vehicles, loaded with explosives and chemicals, into the grounds of the General Intelligence Department in Amman and detonate them, prosecutors said.
The plot also planned to attack the U.S. Embassy, the prime minister's office, and various intelligence and military court officials, the indictment said.
The indictment said that when investigators conducted an experiment with small amounts of the chemicals found with the defendants, it produced "a strong explosion and a poison cloud that spread over an area of 500 square yards."
From the geographical data that mastermind al-Jayousi had collected, it appeared he aimed to kill thousands of people in the chemical attack, the indictment said.
Eight of the defendants were accused of belonging to a previously unknown group, "Kata'eb al-Tawhid" or Battalions of Monotheism, which security officials say is headed by al-Zarqawi and linked to al Qaeda.
The eight were also charged with conspiring to commit acts of terrorism and possession and manufacture of explosives.
Previously, Jordan's military courts have condemned al-Zarqawi to death in absentia for the 2002 assassination of U.S. diplomat Lawrence Foley in Amman and for a failed suicide attack on the Jordanian-Iraqi border in 2004.
By Shafika Mattar