WASHINGTON — The Obama administration has reached a patchwork agreement with congressional leaders to end a 13-day partial shutdown of the Federal Aviation Administration (FAA), Senate Majority Leader Harry Reid said Thursday.

The agreement signals an end, at least for a few weeks, to a standoff that put 4,000 agency employees out of work, idled tens of thousands of workers at hundreds of airport construction projects and cost the federal government more than $350 million in lost taxes on airline tickets.

Congressional officials said the deal arranges rubber-stamp passage by the Senate on Friday of a bill that was approved by the House last month, extending the aviation agency's operations through Sept. 16.

Only a few senators need to be present when the Senate convenes Friday morning, and if no one objects to the request for unanimous consent to pass the House bill, the impasse will officially be over.

"This agreement does not resolve the important differences that still remain," Reid said. "But I believe we should keep Americans working while Congress settles its differences, and this agreement will do exactly that."

The agency had been forced to put "nonessential" employees on an abrupt, unpaid leave, and required some "essential" employees to work without pay. Without the authority to collect ticket taxes from airlines, the agency also has missed out on $350 million in revenue.

While employees could be back to work as early as Monday, it's unclear for how long.

"This issue is still unresolved, as far as I'm concerned," said Dan Stefko, an engineer with the FAA who has been out of work for nearly two weeks. "It could be one and a half months before we could be right back in the same exact spot."

It was uncertain whether Congress would act to restore back pay to the furloughed FAA employees. Tens of thousands of construction workers who have been laid off since July 23 seemed unlikely to recoup their lost wages.

The agreement, in the wake of a nasty and protracted battle over the debt ceiling, was worked out as the Obama administration and Congress were feeling pressure from voters who said they have grown tired of political fights that hurt working Americans and the economy.

Official Washington, D.C., has been peppered in recent days by appeals from labor unions employing furloughed FAA employees and construction workers and letters from trade groups representing airport executives and business groups.

Together, they expressed outrage that Congress left this week on a five-week vacation without resolving the FAA issue, letting $30 million a day in airline ticket and fuel taxes go uncollected because of a dispute over $16.5 million in annual cuts to rural air service.

Senate Democrats had previously refused to pass the House bill because it contained cuts in the Essential Air Service, a subsidy program that helps to pay for commercial airline service to rural airports.

The breakthrough came Thursday when Transportation Secretary Ray LaHood told congressional leaders that he has the authority to issue waivers for the communities affected by the cuts in rural air service contained in the House bill.

The administration had been coordinating discussions for days involving LaHood, House Speaker John Boehner, Reid and others.

In a statement, LaHood said: "This is a tremendous victory for American workers everywhere."

The agreement does not address differences over labor issues that Senate Democrats said were the real reason Republicans were trying to press for the cuts to rural air service.

Material from the Tribune Washington bureau and

The Washington Post

is included in this report.