The donation from Universal, which last week released "United 93," a film about the flight, brings to $9 million the private donations so far. Organizers hope to raise $30 million to build the memorial near Shanksville, Pa., where the plane crashed.
The studio had promised to contribute 10 percent of the film's box office revenue from the first three day of the North American release to the memorial, which is expected to cost about $58 million to build.
The total announced Tuesday represents 10 percent of the opening weekend gross of $11.5 million, and the memorial organizers should have the money by the end of the week, said Michael Moses, an executive at Universal.
The flight was en route to San Francisco from Newark, N.J., when the hijackers took over, probably with the goal of crashing the plane into the White House or the Capitol. Instead, the plane went down in Pennsylvania — apparently after passengers rushed the cockpit — killing the 33 passengers, seven crew members and four hijackers on board.
For the past two years, Rep. Charles H. Taylor, R-N.C., chairman of the House Appropriations subcommittee that oversees the Interior Department, has blocked funding to buy property for the memorial. He has expressed concerns that the project would not receive sufficient private funding and the federal government would be asked to pick up the tab.
"We're optimistic once we have the chance to get him additional facts about our fundraising success to date, that he may have a different perspective," said Hamilton Peterson, president of Families of Flight 93, whose father and stepmother died in the crash.
Taylor could not immediately be reached for comment on Tuesday. His press secretary has said he would not speak about the issue before it came to his panel on Thursday.
Lynn Scarlett, acting director of the Interior Department, told reporters Monday that members of her staff had met with Taylor and subcommittee members and were hopeful the funding would be made available.
Pennsylvania Rep. Bill Shuster, whose district encompasses the crash site, has said along with Pennsylvania Sens. Rick Santorum and Arlen Specter that they are hopeful the federal money will be made available.
The White House requested $5 million for the nearly 1,700-acre site in rural western Pennsylvania as part of a larger spending bill. An additional $5 million is expected to be sought next year.