NEW YORK — Barack Obama will accept the Democratic presidential nomination at Invesco Field at Mile High, a 76,000-seat stadium home to the Denver Broncos, the Democratic National Committee announced today.

The party's convention will be held Aug. 25-28 at Denver's Pepsi Center, which holds up to 21,000 people. Construction for the convention was beginning at the Pepsi Center Monday amid concerns about lagging fundraising and cost overruns.

Last month, the convention's host committee reported it was nearly $12 million short of the $40.6 million it had pledged to raise for the effort. Host committee members spoke openly of needing the Obama campaign's help to close the gap.

The decision to move Obama's acceptance speech to the giant football stadium was expected to boost fundraising, convention organizer Jenny Backus said.

"Lots of conventions have had no connection to their host cities, but this one is really going to take advantage of being in a state that's going to be an important general election battleground," Backus said. "And what better way to kick off the fall campaign and get thousands of supporters and grass roots organizers all in one place to get fired up."

With a heavy influx of younger voters and Hispanics in recent years, Colorado, once heavily Republican, is one of a handful of states in the mountain West that have been trending more Democratic. Both campaigns view it as a general-election swing state; Republican John McCain was kicking off a five-day economy-focused campaign swing in Denver Monday.

The Obama campaign made its own announcement about the new speech venue in a fundraising e-mail to supporters Monday.

"We're going to kick off the general election with an event that opens up the political process the same way we've opened it up throughout this campaign. Barack has made it clear that this is your convention, not his," campaign manager David Plouffe wrote.

The campaign will choose 10 people who contribute at least $5 to the campaign between now and July 31 to fly to the convention and meet Obama backstage before the speech, Plouffe added.

Obama is known for drawing huge crowds to many of his speeches. In May, a record 75,000 jammed into a riverside park in Portland, Ore., to hear him speak shortly before that state's primary.

Obama is scheduled to deliver his acceptance speech on Thursday, Aug. 28, the fourth and final night of the convention. It coincides with the 45th anniversary of Martin Luther King Jr.'s "I Have a Dream" speech on the steps of the Lincoln Memorial in 1963.

If elected, the Illinois senator would be the first black president.