Lockheed Martin said about 3,000 employees would be furloughed on Monday due to the U.S. shutdown.
The company said the number of employees was expected to increase every week if the shutdown continued.
Lockheed said the furloughed employees include those who work at government facilities that have closed and those whose work requires a government inspection that cannot be completed.
A political standoff over the U.S. budget has shut down non-essential government services and hurt companies that rely on federal employees and funding.
(Read more: As shutdown drags on, govt workers seek fast cash)
"I'm disappointed that we must take these actions and we continue to encourage our lawmakers to come together to pass a funding bill that will end this shutdown," Lockheed Chief Executive Marillyn Hewson said.
A number of other U.S. companies have also commented about how the partial government shutdown is affect their business:
Boeing: The aerospace and defense company said there could be delays in its jetliner deliveries, including its new 787 Dreamliner, because thousands of U.S. aviation officials needed to certify the planes have been idled. The delays would also affect numerous programs and products in the company's defense business.
United Technologies:The company, which makes Sikorsky helicopters and other items for the military, said it would be forced to furlough as many as 4,000 employees if the U.S. government shutdown continues through next week, due to the absence of government quality inspectors. More than 5,000 employees may be on furlough if the shutdown continues into next month.
Wal-mart: The retailer's Sam's Club chain saw a slight slowdown last weekend at its warehouse club stores near government facilities but anticipates it could see a lift in food sales if military commissaries remain closed, the unit's CEO Rosalind Brewer told Reuters. The chain is letting military families shop without paying a membership fee at 50 outlets located near military bases, Brewer said.
(Read more: Reason for optimism, and fear, in budget battle)
USEC: The uranium fuel supplier, which is awaiting funds from the U.S. government for an enrichment project, said it may have to furlough some workers or slow down work at the project if the shutdown extends past Oct. 15.
Chief executives from major financial institutions have warned of "adverse" consequences if government agencies remain closed and lawmakers fail to raise the debt ceiling by mid-October. In a meeting with Obama on Wednesday, Goldman Sachs Chief Executive Lloyd Blankfein implicitly criticized Republicans for using their opposition to the healthcare law as a weapon that could lead to a U.S. default.