Democratic presidential hopefuls Sen. Barack Obama, D-Ill., left, laughs with Sen. Joseph Biden, D-Del., before the start of a presidential forum hosted by the AFL-CIO at Soldier Field in Chicago, in this Tuesday, Aug. 7, 2007 file photo. Sen. Joe Biden of Delaware is Barack Obama's pick as vice presidential running mate, The Associated Press has learned Saturday Aug. 23, 2008. (AP Photo/Charles Rex Arbogast, FILE)

WASHINGTON (AP) -- Barack Obama selected Sen. Joe Biden of Delaware late Friday night to be his vice presidential running mate, according to a Democratic official, balancing his ticket with an older congressional veteran well-versed in foreign policy and defense issues.

Biden, who has twice sought the White House, is a Catholic with blue-collar roots, a generally liberal voting record and a reputation as a long-winded orator.

Across more than 30 years in the Senate, he has served at various times not only as chairman of the Foreign Relations Committee, but also as head of the Judiciary Committee, with its jurisdiction over anti-crime legislation, Supreme Court nominees and Constitutional issues.

The official who spoke did so on condition of anonymity, preferring not to pre-empt a text-message announcement the Obama campaign promised for Saturday morning.

Obama's campaign arranged a debut for the newly minted ticket on Saturday outside the Old State Capitol in Springfield, Ill.

The Democratic National Convention meets next week in Denver to hand Obama his long-sought presidential nomination, and then confirm Biden.

In selecting Biden, Obama passed over former first lady Hillary Rodham Clinton, his tenacious rival across months of primaries and caucuses.

Even so, Obama has gone to great lengths to gain the confidence of her primary voters, agreeing to allow her name to be placed in nomination at the convention and permitting a roll call vote that threatens to expose lingering divisions.

Biden slowly emerged as Obama's choice across a long day and night of political suspense as other contenders gradually fell away.

First Virginia Gov. Tim Kaine let it be known that he had been ruled out. Then came word that Sen. Evan Bayh of Indiana had also been passed over.

Several aides to Clinton said the Obama campaign had never requested financial or other records from her.

Other finalists in the veep sweepstakes were Kansas Gov. Kathleen Sebelius and Texas Rep. Chet Edwards.

Among those on the short list, Biden brought the most experience in defense or foreign policy -- areas in which Obama is rated relatively poorly in the polls compared with Republican Sen. John McCain.

While the war in Iraq has been supplanted as the campaign's top issues by the economy in recent months, the recent Russian invasion of Georgia has returned foreign policy to the forefront.

A native of Scranton, Pa., Biden also has working-class roots that could benefit Obama, who lost the blue-collar vote to Clinton during their competition for the presidential nomination.

Biden was elected to the Senate at the age of 29 in 1973.

He spent the day at his home in Delaware with friends and family. The normally loquacious lawmaker maintained a low profile as associates said they believed -- but did not know -- he would be tapped. They added they had been asked to stand by in case their help was needed.

No sooner had word spread of his selection than McCain's campaign unleashed its first volley. Spokesman Ben Porritt said in a statement that Biden had "denounced Barack Obama's poor foreign policy judgment and has strongly argued in his own words what Americans are quickly realizing -- that Barack Obama is not ready to be president."

As evidence, Republicans cited an ABC interview from August 2007, in which Biden said he would stand by an earlier statement that Obama was not ready to serve as president.