The company expects to put nearly 2,000 employees out of work at its Sirkosky helicopter unit on Monday. The number could double through the week at its Pratt & Whitney and UTC Aerospace Systems businesses also get affected.

More than 5,000 employees may be on furlough if the shutdown continues into next month due to the absence of Defense Contract Management Agency inspectors who audit and approve manufacturing operations for military products, UTC said.

The federal government has come to a halt, except for essential services, after Congress was unable to reach an agreement on funding for the new fiscal year because of a standoff over healthcare reforms.

Sikorsky, which makes military and commercial helicopters, gets about 66 percent of its revenue from the U.S. government, UTC filings showed. Sales to the government accounted for 27 percent of revenue in 2012 for engine maker Pratt & Whitney.

Hartford, Connecticut-based United Tech shares were unchanged in extended trade after closing down 2 percent at $104.98 on the New York Stock Exchange on Wednesday.

(Reporting by Mridhula Raghavan in Bangalore)