The Bush administration has set requirements for the headquarters of the Department of Homeland Security that appear to favor a suburban office park rather than a site in the District, according to a government document and sources familiar with the search.

These sources caution that the decision, which has broad symbolic importance for the future of security-conscious federal agencies in the post-Sept. 11 era, is being made very quickly and that the agency's approach could change before a decision is announced. The agency, for instance, could spend its first several years in a temporary headquarters while a more permanent site is found, a move that would improve the District's chances of being the agency's eventual home. But these sources say the agency would strongly consider an office-park setting that it could expand into and make its permanent home.

The search has set off a vigorous competition among the governors of Maryland and Virginia and the mayor of the District. Each jurisdiction hopes to reap the potential bonanza of security-related jobs. D.C. officials are pushing to keep federal government offices in the city, even as some experts recommend dispersing the jobs in scattered office parks and campuses in the outer suburbs.

While only a few hundred workers would be in the headquarters initially, the Homeland Security Department could ultimately have thousands of workers at a large campus and attract thousands more from private contractors nearby.

"Everybody is jockeying for the department," said Carrie Cantrell, a spokeswoman for Virginia Sen. George Allen (R). "It's like any other economic-development strategy that you have. You recruit to your home state."

About 181,000, or 55 percent, of the region's 340,000 federal jobs are based in the District. The rest are split nearly evenly between suburban Maryland, with 74,000 federal workers, and Northern Virginia, with 79,000.

A 1947 law requires Cabinet agency headquarters to be in the District except by an act of Congress, such as the one establishing the Pentagon in Arlington. Administration officials have said they will seek such an authorization if necessary. Each of five key Homeland Security component agencies are now based in Washington.

On Nov. 20, the General Services Administration, which handles federal real estate, issued a notice on a Web site for government contractors describing the government's need to lease between 225,000 and 275,000 square feet of office space for five to 10 years, with occupancy beginning in June 2003. The document does not state who the tenant would be, but sources familiar with the matter said this week that it is Homeland Security.

A GSA spokesman declined to comment and referred questions to the Office of Homeland Security. A spokesman there said that the agency had not yet made a decision on its headquarters but that one could come within weeks. "The transition office is looking at a variety of locations for not only the start-up needs of this department, but its long-term needs as well," Gordon Johndroe said.

The GSA document says that the office space could be in the central employment area of the District, Fairfax or Loudoun counties in Virginia, or Prince George's or Montgomery counties in Maryland. Arlington and Alexandria were not included on the list, nor were outer suburbs other than Loudoun County, although one source said the document was not meant to establish the geographical limits on the site.

Moreover, while the District is listed as a possibility in the document, it also calls for the office space to be in buildings close to each other "as in an office park setting enabling a securable perimeter." Some in the real estate industry said that such a space is unlikely to be found in the District, where there are few large, contiguous blocks of office space available and even fewer that offer the setbacks from city streets that the GSA notice also inquires about.

Such a headquarters could be built in the District in any of several locations, these sources said, including the Southeast Federal Center and the campus of St. Elizabeths Hospital. But it would be nearly impossible for such facilities to be ready by the June 2003 deadline set by the GSA notice.

Spokesmen for two Virginia members of Congress said that conversations with GSA and Homeland Security officials led them to conclude that the contest is down to Virginia and Maryland because the District lacks a location with adequate space.

"They said it's going to be Maryland or Virginia, because the District is not feasible," one Virginia aide said.

Maryland and D.C. representatives said Virginia has a political edge as a Republican-friendly state represented by influential Republicans -- Senate Armed Services Committee Chairman John W. Warner, House GOP campaign chief Rep. Thomas M. Davis III and Allen, the incoming Senate GOP campaign head.

"I believe enough space for this facility exists in D.C.," said Del. Eleanor Holmes Norton (D-D.C.), who asked Mayor Anthony A. Williams (D) to press the case personally to President Bush and his nominee for Homeland Security secretary, Tom Ridge, not to damage the city's economy or break with precedent by headquartering a non-defense Cabinet agency outside the District. "If this decision is made on a political basis, I would be greatly disappointed in the White House, because they have shown some sensitivity to the needs of this city."

Norton said the limited size of the lease request was a hopeful sign that the District would have time to make its case. Because new construction would take years, sources say, Homeland Security needs to lease existing office space for the immediate future.

Sources familiar with the GSA's notice caution that the agency was only seeking to get a list of possibilities for a headquarters for the agency. They said the agency wanted to be able to have a list of options to show those making the decision. The president makes the final decision.

Under the Homeland Security Act signed by Bush on Nov. 25, the White House has 60 days from that date to detail the organization and location of the new department to Congress, which will have to authorize any lease for headquarters.

The space sought under the GSA notice is relatively small; in a typical space allocation, there would be enough room for about 1,000 workers. The agency is to employ 170,000. But the notice calls for the option of expansion space up to 250,000 square feet. The vast majority of the Homeland Security Department's workers are from the 22 existing federal agencies that make up the new agency, including the Coast Guard, the Secret Service and the Immigration and Naturalization Service, which already have their own facilities.