Former top White House aide Lewis "Scooter" Libby has been found guilty of obstruction of justice and perjury in connection with the scandal over the leak of a CIA agent's identity.
Libby, a former top aide to Vice President Dick Cheney, was convicted on four out of five counts in the case, after a trial that highlighted the White House's campaign to justify the war in Iraq.
He was found guilty of one count of obstruction of justice, one of making false statements to the Federal Bureau of Investigation, and two counts of perjury.
A White House spokeswoman said shortly after the verdict was announced that President George W. Bush "respected the jury's verdict, that he was saddened for Scooter Libby and his family."
But spokeswoman Dana Perino refused to discuss whether Bush would consider pardoning 56-year-old Libby, saying she was "aware of no such request."
Charges against Cheney's former chief of staff were brought by a special prosecutor investigating the source of the leak of the identity of CIA agent Valerie Plame, whose husband, ex-diplomat Joe Wilson, was a vocal critic of the Iraq war.
Bush's critics charge senior officials deliberately disclosed Plame's identity to punish her husband for criticising the White House's rationale for the war.
Senate Majority Leader Harry Reid said the verdict held the White House accountable for distorting intelligence ahead of the war.
"I welcome the jury's verdict. It's about time someone in the Bush administration has been held accountable for the campaign to manipulate intelligence and discredit war critics," Reid said in a statement.
The trial "revealed deeper truths about Vice President Cheney's role in this sordid affair. Now President Bush must pledge not to pardon Libby for his criminal conduct," Reid said.
A grim-faced Libby made no comment as he left the courthouse with his defence team, but his lawyer said they plan to file for a new trial, and if that is rejected they will appeal the verdict.
"We are very disappointed in the verdict of the jurors," lawyer Theodore Wells said. "We have every confidence that, ultimately, Mr. Libby will be vindicated."
Libby had faced a total of 30 years in prison, including 10 years on the obstruction of justice count, and fines of up to $US1.2 million ($A1.56 million) dollars.
Sentencing in the case will be handed down on June 5.
Libby, who had pleaded not guilty to the charges, remained seated impassively inside the court as the verdict was read on the 10th day of the jury's deliberations after the trial started in January.
According to White House critics, Cheney's office in mid-2003 sought to undermine diplomat Joe Wilson's claims that Niger had not supplied uranium to Iraq.
His claims contradicted allegations by the Bush administration that Iraqi leader Saddam Hussein had sought the uranium to build a nuclear weapon.
By leaking Plame's name, the White House allegedly sought to tie Wilson to an anti-Bush administration faction in the Central Intelligence Agency, critics charged.
The trial lifted the lid on how deep the obsession ran inside the White House with news coverge of the administration's justification for the Iraq war, and exposed the vice president's office to unflattering scrutiny.
The case dates from the feverish days before the US-led invasion of Iraq in 2003 when the Bush administration used intelligence purportedly showing that Saddam already had, or was bent on acquiring, weapons of mass destruction.
Wilson, a former US ambassador to Gabon, was sent to Niger in February 2002 to investigate claims Saddam tried to buy uranium for nuclear bombs but concluded it was doubtful such transfers took place.
The claim still found its way into Bush's annual state of the union address a year later, prompting Wilson six months later to unleash a New York Times article in which he warned top US officials may have ignored data which contradicted the case for war.
