. Lewis "Scooter" Libby, the former chief of staff of U.S. Vice President Dick Cheney, was sentenced to 30 months in jail on Tuesday for lying and obstructing investigators in the CIA leak case.

"People who occupy these types of positions, where they have the welfare and security of nation in their hands, have a special obligation to not do anything that might create a problem," said U. S. District Judge Reggie B. Walton.

Libby was also fined 250,000 U.S. dollars and placed on probation for two years following his release from prison.

His 30-month sentence was for the obstruction of justice charge.

Libby also received shorter sentences on the other counts, to run concurrently.

He was convicted on March 6 of four counts in a five-count indictment alleging perjury, obstruction of justice and making false statements to the FBI.

The charges arose from a federal probe into how the identity of Valerie Plame, then a covert CIA agent, was given to reporters in the summer of 2003.

Libby, 56, had served as Cheney's chief of staff and national security adviser between 2001 and October 2005, when he resigned after being indicted in the leak case.

Under federal sentencing guidelines, Libby -- if imprisoned -- must serve at least 80 percent of his sentence, or two years.

Neither Libby nor his attorneys spoke to reporters as they rushed to their car and left the courthouse.

News reports said he will appeal the verdict.

Libby has maintained his innocence ever since he was indicted and resigned in October 2005.

The case involves statements Libby made to the FBI and a grand jury during their probe into how the covert identity of CIA operative Plame was leaked.

Some in the United States believe the whole Bush administration was behind the leak and the former chief of staff to Cheney was just a "scapegoat."

Plame's name became public when Robert Novak named her in his New York Times column on July 14, 2003.

Her husband, former ambassador Joseph Wilson, had openly questioned the Bush administration's basis for invading Iraq, which raised the question that if the White House deliberately leaked his wife's identity to embarrass and discredit him.

Cheney has continued to express support and empathy for his former chief of staff, and it is possible Libby could be granted a presidential pardon before the end of Bush's term.

But White House spokeswoman Dana Perino said Bush will not intervene in the case with a pardon at this point, when she spoke to reporters traveling with the president to the Group of Eight leaders' summit in Heiligendamm, Germany.

"The president has not intervened so far in this or any other criminal matter and so he is going to decline to do so now as well. " She said, "The criminal justice system is still continuing."