Aug. 27 (Bloomberg) -- Hillary Clinton released the convention delegates who were pledged to her, freeing them to vote to nominate her one-time rival Barack Obama as the Democratic presidential candidate.

``I am here today to release you,'' Clinton told more than 1,000 of her delegates gathered at the Colorado Convention Center in Denver. She said she recognized that many of them felt a duty to vote for her, and said, ``I am not telling you what to do. I signed my ballot this morning for Senator Obama.''

She addressed her supporters a little more than an hour before her name was placed in nomination by Dolores Huerta, a delegate from California. Michael Wilson, an Iraq war veteran, followed to place Obama's name in nomination.

Obama is set to formally become the Democratic nominee this afternoon in Denver after a roll-call vote of state delegations. He arrived in the city just before the vote, coming from a campaign event in Montana.

Clinton's gesture today was intended to unify the Democratic Party and tamp down any lingering resentment among her supporters. Divisions between the two camps have been a subtext of this week's convention, and Obama's task is to get the party focused on the general-election battle against Republican John McCain.

Name in Nomination

Clinton, a New York senator, won more than 1,700 pledged delegates, short of the number required to win nomination, during a protracted primary battle with Obama. Her name was placed in nomination today to recognize the 18 million voters who backed her.

Many of Clinton's delegates had already cast ballots for her with their state delegations in the morning, and some groaned with disappointment at the formal release. Still, the crowd reacted with enthusiastic applause when Clinton talked about the importance of electing Illinois Senator Obama.

``We realized that she would release us, but we thought we would honor her,'' said Kathy Karpan, 65, a Wyoming delegate who cast her ballot for Clinton this morning. She said right after the vote, her delegation was united in support of Obama.

In a prime-time convention speech last night, Clinton said she was proud to be an Obama supporter and urged all her backers to line up behind him. Today's roll-call vote will make Obama the first black presidential nominee of a major political party.

Show of Unity

Clinton said today that it's important that ``at the end of today we will nominate Barack Obama and Joe Biden,'' whom Obama chose as his running mate.

Clinton reprised much of her speech from the previous night, in which she told her backers it was crucial to have a Democrat in the White House to tackle pressing issues such as affordable health care for all Americans.

Her husband, former President Bill Clinton, is scheduled to address the convention tonight.

Obama campaigned today in Montana as part of his effort to remake the electoral map by peeling away traditional Republican strongholds. If he succeeds in Montana, it will mark the third time since 1948 that the Western state has gone Democratic in a presidential race.

In keeping with the day's convention theme, he pledged to a group of about 225 veterans and military family members to improve conditions for veterans in the state if elected commander-in-chief.

``As president I'm going to make sure that the VA system in Montana gets the oversight, the direction and the resources it needs to do the job,'' Obama said.

To contact the reporters on this story: Kristin Jensen in Denver at kjensen@bloomberg.net; Catherine Dodge in Denver at cdodge1@bloomberg.net

Last Updated: August 27, 2008 17:44 EDT