A judge in Denver has rejected a defence request to block the death penalty because Nichols was found not guilty of murder.

The jury in the second Oklahoma City bombing trial convicted Nichols of conspiracy and involuntary manslaughter for the 1995 attack that killed 168 people.

The BBC's Bill Turnbull discusses the Nichols verdict (Dur: 1'-26")

The jury, which deliberated for 41 hours over six days, stopped short of finding the former farmhand guilty of first degree murder, which carries the death penalty.

He was convicted of the lesser, non-capital offence of involuntary manslaughter. However, the conspiracy count could result in a death sentence.

Jurors will now be asked to decide if Nichols should face the death sentence. His defence will argue that the court has no right to consider that.

The Oklahoma plot was hatched after McVeigh and Nichols watched the Waco siege on television

The murder charges referred to eight federal agents who died in the April 19, 1995, blast at the Alfred P. Murrah government office building.

Afterwards, Tom Kight, whose stepdaughter died in the bombing, said: "It's a very hollow and shallow victory.

"I guess those 12 jurors saw something different than I saw. It's an empty feeling."

Prosecutors argued that Nichols worked side by side with his old army friend Timothy McVeigh, who has already been sentenced to death for the bombing, to avenge what they believed were abuses of power by the American government.

The BBC's Jason Dasey reports from Denver. (Dur:1'00")

The Oklahoma bomb was detonated exactly two years after federal agents stormed the Branch Davidian compound in Waco, Texas. Dozens of sect members died in the ensuing fire.

McVeigh and Nichols watched the Waco siege and fire on television together, the prosecution maintained.

The Oklahoma bombing prosecutor, Larry Mackey

Nichols was hundreds of miles from Oklahoma when the explosion ripped through the Alfred P Murrah building but a receipt tied him to the purchase of fertiliser used to make the bomb.

In his home investigators found a drill bit which, the prosecution said, was used in the theft of detonators and phone records showed him to be in regular contact with McVeigh.

During the trial Nichols' defence stressed he was in Herington, Kansas, with his family at the time of the attack.

Vital clue: This receipt linked Nichols to the purchase of fertiliser used in explosives

Nichols' attorneys also argued that he and McVeigh were merely business associates who sold military surplus goods at gun shows, that Nichols knew nothing of the plot and that unidentified co-conspirators helped McVeigh build the powerful fertilizer-based truck bomb.