The $12.8 billion bid to operate the Pennsylvania Turnpike for 75 years, announced on Monday by Governor Rendell, is likely to undergo significant scrutiny in the coming weeks, which could extend beyond the June 20 bid expiration date.

The high bid was submitted by a consortium that includes Spanish toll-road operator Abertis Infraestructuras and U.S. investment bank Citigroup. An Abertis official said the consortium would probably be flexible regarding the deadline, but he did not offer specifics.

In announcing the bids, Governor Rendell said the lease would generate 13 percent more revenue for transportation than what is to be generated under the current plan, which includes tolling Interstate 80.

The projection is based on the performance of the Pennsylvania State Employee Retirement System during the last 20 years. However, the House Transportation Committee commissioned a study several months ago concluding that had the Turnpike lease been consummated 10 years ago, the principal would have eroded by 27 percent due to below-average returns in the initial years.

PHIA President Ron Drnevich said more revenue for transportation infrastructure, while welcome, still will leave a funding gap totaling several hundreds of millions of dollars annually.

“The fact that at least one analysis shows the principal eroding certainly begs for very close scrutiny,” Drnevich said. “When you monetize an asset for 75 years, it’s essential to ensure that the principal remains intact for the entire period. The last thing we want is for the funding source to disappear long before the lease expires.”

Of equal concern is how to assure that the proceeds will always be dedicated for transportation purposes, he said.

“It may be that a constitutional amendment is the only way to assure that,” Drnevich noted. “Including such a requirement through the legislative process can be undone just as easily by a future General Assembly and governor.”