"I'm hopeful we can have 102 votes we need," he said. "We will work on that tonight and tomorrow."
If the measure passes, it would position the legislation for negotiation with Senate Republican leaders and Gov. Rendell as early as this week.
After more than five hours of debate, the House approved an amendment offered by Rep. Kate Harper (R., Montgomery) that would set aside 60 percent of revenue from the tax for local governments and the environment and 40 percent for the general fund.
The General Assembly has wrestled for several years with taxing the lucrative Marcellus Shale reserve, which underlies most of the state.
Newly developed deep-well technology has allowed gas companies to reach the deposits, setting off a drilling boom that has brought thousands of jobs and millions of dollars in investment, but also increased environmental concerns about contamination to the water supply.
Senate Republicans, who control that chamber, had pronounced an earlier bill that moved out of committee Monday dead on arrival because of what they call an unreasonably high tax rate on the industry.
Eachus said the new bill offered the opportunity for Pennsylvania to "face its most serious environmental challenge" since coal mining began.
Rendell said he would support the House Democrats' plan because the tax - which would generate $300 million - was close to what he was seeking.
"We hope this will be a starting point for negotiations," said Rendell's spokesman, Gary Tuma.
The General Assembly has little time to reach a deal with the Senate, which meets on only four days before the end of the year. The House has scheduled additional sessions after the Nov. 2 election.
The legislation would impose a tax of 39 cents per 1,000 cubic feet of natural gas extracted, roughly 10 percent based on current gas prices, a figure the industry and House Republicans said would be the highest in the nation.
