The decision to accept corporate money reverses Mr. Obama’s policy from 2009, when he refused corporate donations and capped individual donations at $50,000 per person or $100,000 per couple. Mr. Obama also barred corporations from helping finance this year’s Democratic National Convention.

But after the most expensive campaign in presidential history — Mr. Obama, the Democratic National Committee and the party’s joint fund-raising efforts took in $1.14 billion — many of the president’s contributors are feeling worn out, and the committee concluded that it would be difficult to raise the tens of millions of dollars it needed for the parade, inaugural balls and other events.

“Our goal is to make sure that we will meet the fund-raising requirements for this civic event after the most expensive presidential campaign in history,” the spokeswoman, Addie Whisenant, said in a statement, adding that donors’ names would be posted on a Web site “to ensure continued transparency.”

The question of whether the Presidential Inaugural Committee would accept corporate money has been a thorny one for Mr. Obama. Companies that donate money may have business before the White House, raising questions of conflict of interest. Committee officials said its lawyers would vet each donor, and those with conflicts would not be permitted to give.

But government watchdog groups sharply criticized the decision and accused Mr. Obama of abandoning his principles. “It’s very disappointing,” said Robert Weissman, president of the advocacy group Public Citizen, which wrote to Mr. Obama last month urging him to reject corporate money. “There’s no corporation which has no conflict of interest. It’s really a terrible reversal of the decision they made in 2009.”