HARRISBURG -- At least two and possibly three firms have submitted bids for a 75-year lease of the Pennsylvania Turnpike and Gov. Ed Rendell is giving them until Friday to enhance their proposals.

The results will not be announced until "early next week, perhaps Monday," said the governor's press secretary, Chuck Ardo.

Otherwise, Mr. Rendell revealed little about a possible deal for the nation's oldest superhighway at a news conference yesterday, including not identifying the prospects.

He said because multiple bidders have submitted offers within 10 percent of each other, the state is required to solicit "best-and-final offers."

"Full details will be made public once we have the highest bid, but for now my responsibility is to assure that the commonwealth receives the highest possible bids," Mr. Rendell said of his quest for an alternate funding source for the state's roads, bridges and public transit systems.

Neither the governor nor his deputy chief of staff, Roy Kienitz, would reveal the amounts of bids received thus far or the financial investment firms submitting them. Mr. Kienitz last week predicted the range would be "at the lower end" of estimates between $12 billion and $16 billion.

If the upfront payment from the high bidder can yield $1 billion a year or more in investment proceeds, he said, Mr. Rendell will seek speedy legislative approval for privatizing the 360-mile east-west mainline and 110-mile Northeast Extension. Mr. Rendell also would attempt to withdraw a proposal to toll Interstate 80, which was included in the Act 44 transportation funding package that he signed last year.

Mr. Rendell said whoever wins the turnpike lease would carry out the 25 percent toll increase that is to be implemented by the turnpike commission in January under terms of Act 44.

"Any lease deal must guarantee that we keep the turnpike safe, affordable and well-maintained for future generations," he said. "We will continue to work hard to ensure that a private operator will be held to the highest standards of performance."

A lease would impose a cap on future tolls, protect current turnpike workers and complete scheduled improvements, like widening the highway to three lanes in each direction between Irwin and New Stanton.

Several leading legislators have said they want to examine all bids and know the members of each bid consortium, the number of foreign participants and details of monetary differences in the bids.

The Wall Street Journal and Reuters news service identified two suitors -- Spanish toll road operator Abertis Infraestructuras SA and a consortium of Cintra Concesiones de Infraestructuras de Transport SA, also of Spain, and Macquarie Infrastructure Group, of Australia.

Other sources mentioned a third, a consortium of Goldman Sachs, a New York-headquartered global investment firm, and Transurban Group, an international toll road manager.

Cintra/Macquarie paid $1.83 billion in 2005 for a 99-year lease of the 8-mile Chicago Skyway and $3.85 billion in 2006 for a 75-year lease of the 157-mile Indiana Toll Road.

Transurban paid $611 million in 2006 for a 99-year lease of the 9-mile Pocahontas 895 toll road near Richmond, Va., and is now involved in a project including High Occupancy Toll lanes on Interstate 495, the Capital Beltway around Washington, D.C.

While Abertis operates about 4,000 miles of highways in Europe, it has none in the United States.

It does, however, operate several airports.

Turnpike officials have been fighting Mr. Rendell and his efforts to lease the road to a private operator, arguing that the partnership created under Act 44 better serves the state's transportation funding needs for the next 50 years. The turnpike already has provided the Pennsylvania Department of Transportation with $750 million for the current fiscal year that ends June 30 and is poised to provide $850 million for the 2008-09 fiscal year.