Developers, real estate agents and investors will watch closely today as a nine-member commission opens hearings on proposed military base closings in the region, hunting for information that could begin shaping investment decisions and commercial lease negotiations in Northern Virginia, Maryland and the District.

The Pentagon's preliminary recommendations would shift tens of thousands of military personnel from old facilities such as the Walter Reed Army Medical Center in Northwest Washington and also leave vacant millions of square feet of commercial office space that the Defense Department leases in Crystal City and other area locations.

The Base Realignment and Closure Commission will send final recommendations to President Bush later this year. The tenor at today's hearings could offer clues about whether to buy or sell, negotiate a new lease, or walk away from the expiring one.

"Most of the real estate community is in a wait-and-see mode," said Kurt Stout, a senior vice president at the real estate firm Grubb & Ellis Co. Stout specializes in leasing space to the federal government and plans to attend one of the hearings this afternoon in Northern Virginia. "Sellers are waiting to see if they should sell and tenants are watching to see what it all does to rents. . . . We're looking to see if there's any nuggets that come out of these hearings so we can tell our clients what we think they should do," Stout said.

"Any sane, knowledgeable investor is not going to touch a building that's going to be impacted by base closings and agencies leaving," said Benjamin B. Lacy, chairman of Lacy Ltd., which advises a large German mutual fund on investing in U.S. real estate. "The reason is that you could conceivably be buying an empty building."

Today will be the commission's chance to hear from local and federal politicians, some of whom will see major job losses in their jurisdictions, and others who will get more workers. Two hearings are scheduled for occur today: one on Capitol Hill that will deal with the 6,000 jobs that are expected to leave the city, the other in an Arlington hotel to discuss the effect on Virginia. A hearing will be held on Friday for base closings in Maryland.

Rep. James P. Moran Jr. (D-Va.) said in an interview that it is not cost-effective or productive to move agencies from Northern Virginia to other parts of the state, as the commission has proposed.

"There seems to be an arbitrary approach to the closure of these offices," said Moran, who is to testify today. "I don't want to see . . . jobs leave Northern Virginia. The agencies aren't going to be able to function as well because they're going to lose . . . employees who don't want to leave Northern Virginia because they've got spouses with jobs here or kids in school."

Northern Virginia is expected to be the hardest hit by the proposed base closings because it would lose roughly 23,000 jobs, and possibly as many as 50,000, from workers housed in dozens of Northern Virginia office buildings the Pentagon leases.

The Pentagon says the buildings do not meet stringent security requirements put in place after Sept. 11, 2001. In the coming years, workers who do various duties, from managing military commissaries to developing missile defense programs, would abandon about 7.2 million square feet of office space -- most of it in Crystal City -- if the commission's recommendations pass. According to Jim Hunter, a real estate broker at Cassidy & Pinkard who represents landlords, the vacancy rate in the Crystal City area is hovering at around 27 percent but could go higher as more space gets dumped back on the market.

For some tenants looking for space, that could mean cheaper rent.

"Arlington is going to see some 7 million square feet come back on the market and that's a lot of space [for tenants to lease]," Hunter said. "It's going to be very upsetting to property owners if all of this goes into place because it will be a long time to absorb all the space that the Defense Department is leaving."