HARRISBURG — High-ranking Pennsylvania state lawmakers sent a revised budget plan to Gov. Ed Rendell after a marathon bargaining session that ended at midnight Wednesday, but the governor's top aide said key details still needed to be clarified.

Elements of the potential breakthrough offer to end the state's 79-day budget impasse were not disclosed, and the legislators involved in producing it said little to reporters after the meeting.

"We've put forth an offer to the governor, and we're waiting to hear back," said House Speaker Keith McCall, D-Carbon.

Rendell Chief of Staff Steve Crawford described the details as "sketchy," adding that "there are differences of opinion on what this revenue package is between the caucuses."

Crawford said the offer did not clearly resolve one of Rendell's main concerns, that the plan will produce sufficient revenue to adequately address projected shortfalls in the coming years.

"What I look forward to seeing is a bona fide and certified list of revenues that would represent a sustainable package, and that's something that, once determined, we would take to the governor and discuss," Crawford said. "I think they've made some good progress today, working toward the goal of sustainability. The question is, how much progress?"

It was an anticlimactic and somewhat mystifying end to what had been hours of discussions among senior legislative leaders conducted inside the Capitol offices of Republican Lt. Gov. Joe Scarnati, who also is the top-ranking state senator.

Earlier in the night, participants had expressed a sense that a solution was at hand and that they hoped they could close the deal.

They also emphasized that the size of the budget and the new revenues needed to pay for it had not changed since three of the four legislative caucuses announced a tentative "framework" $27.95 billion budget deal Friday.

They said they had shifted money around to reflect more of Rendell's priorities. Rendell has threatened to veto the budget if it gets to his desk without significant revisions.