DENVER -- United Airlines and its chief executive officer Glenn Tilton plan to unveil its restructuring plan to its board of directors on Thursday, but there are already widespread rumors of huge layoffs and substantial cutbacks in service.

Union leaders complain that United has kept them in the dark on most of the details of the new business plan.

The Chicago Tribune has reported on some details of the plan.

Among the proposals being considered is cutting about 25 percent of United's remaining pilots and flight attendants, shifting more flights to United's regional express carriers, closing United's maintenance facility in Indianapolis and creating a discount airline subsidiary similar to Southwest Airlines.

UNITED AIRLINES United's Bankruptcy Info History Of United Frequent Flyer? United Airlines FACTS United has 81,000 employees worldwide. United is 55 percent employee owned. Operates 1,700 flights a day, or 20 percent of all U.S. flights. Has most extensive worldwide route structure of any airline.

The newspaper reported that United wants to implement a two-tier pay structure so that pilots and flight attendants who work for the planned new discount carrier would be paid significantly less than those on regular United flights.

The pilots' union has already lashed out at the company's plans for a new discount carrier, vowing to fight it "by every lawful means available."

Currently, United has about 78,000 employees, including nearly 20,000 flight attendants and about 8,500 pilots.

Under the reorganization, United would need only about 6,000 pilots and they would be forced to boost their monthly flight time from the current 36 hours to 50 hours.

Some experts say the plan would cut United's operations here in Denver by about 15 percent.

On Friday, the company reports financial results for its fourth quarter and full year. Those losses are expected to beat last year's $2.1 billion shortfall.

United, the dominant carrier at Denver International Airport, has posted heavy losses since mid-2000. United filed for Chapter 11 federal bankruptcy protection on Dec. 9.

United is required to compile a new business plan in the first 120 days of bankruptcy to show its lenders how it intends to return to profitability.