WASHINGTON, Nov 12 (Reuters) - U.S. flight cancellations

have fallen sharply over the last day as air traffic control

absences shrank just hours before the House of Representatives

is set to vote on a bill on Wednesday to end a record-setting

government shutdown.

Airlines in the United States canceled nearly 900 flights on

Wednesday - the fewest in six days - under a Federal Aviation

Administration requirement they cancel 6% of flights at the 40

busiest airports to address safety concerns. Some airlines told

Reuters they think the FAA will reduce a planned 8% flight cut

on Thursday to 6%. Air traffic control absences accounted for

just 1% of delays on Tuesday, compared with 5% on average before

the shutdown, the FAA said.

Several airlines have canceled only around 6% of flights for

Thursday.

DELAYS REDUCED SHARPLY

Mandated flight reductions are set to rise to 10% on Friday.

Flight operations are improving dramatically, with just 750

delays on Wednesday compared with 4,000 on Tuesday and nearly

10,000 on Monday.

Transportation Secretary Sean Duffy said air traffic

controllers will get a lump sum payment equal to 70% of their

back pay within 48 hours of the shutdown ending.

Delta Air Lines ( DAL ) CEO Ed Bastian told CNBC he thinks the

aviation system will be largely back to normal this weekend, but

said the recent cancellations will cost the airlines a

significant amount. "By the weekend, I think things should be in

good shape," Bastian said.

Air traffic absences have led to tens of thousands of flight

cancellations and delays since October 1, when the shutdown

began. Over the weekend, 1.2 million passengers were delayed or

had flights cancelled due to air traffic controller absences.

The shutdown, the longest in U.S. history, has forced 13,000

air traffic controllers and 50,000 Transportation Security

Administration agents to work without pay.

The FAA is about 3,500 air traffic controllers short of

targeted staffing levels. Many had been working mandatory

overtime and six-day weeks even before the shutdown.