HARRISBURG - In a burst of last-minute activity, the Pennsylvania Senate wrapped up its final scheduled work day of the 2009-10 legislative session by approving dozens of bills on an array of topics, from the controversy-plagued Delaware River Port Authority to pension funds, gun owners' rights, and overcrowded prisons.

The chamber took no action, however, on the 800-pound gorilla in the room: the proposed imposition of a tax on natural gas extracted from the Marcellus Shale.

Senate leaders say that if an agreement is reached with the House and Gov. Rendell on a natural-gas tax in coming days, they may yet schedule days next week to vote on the proposal.

Proposals to tax the state's newest growth industry - drilling operations in the gas-rich Marcellus formation - have risen and fallen for the last two years. Rendell and other Democrats generally support such a tax as a way to bulk up the state's recession-depleted revenues and fund environmental protections. Republicans warn that too steep a tax could drive drillers away.

Most measures approved Thursday by the GOP-controlled Senate now go to the state House, where Democrats have a slight edge. Among them:

Pensions. The Senate approved, 41-8, a bill overhauling the pension plan for government employees to address multibillion-dollar debts looming over depleted pension funds.

The bill is designed to generate $3 billion in savings for Pennsylvania's public-employee and teacher pension funds while addressing an impending spike in payouts from those funds, said sponsor Sen. Pat Browne (R., Lehigh).

But the measure may face a rough ride through the House. Shortly after it passed, House Democratic leaders issued a statement saying the Legislative Reference Bureau had found the bill unconstitutional because it violates the single-subject rule of the state constitution.

Under the bill, pension-plan benefits would be rolled back 25 percent, to pre-2001 levels, and the vesting period would be increased from five years to 10.

Browne's measure also stipulates that employees would have to compile a combination of age and years of service that totals 92 to receive full retirement benefits.

The bill also creates an Independent Fiscal Office, a nonpartisan bicameral agency that would develop state-revenue estimates and analyze spending proposals. The office is the brainchild of Senate Republicans, who have sparred with Rendell and House Democrats over revenue estimates.

Rendell and House Appropriations Chairman Dwight Evans (D., Phila.) have called such an office an unneeded expense. But Rendell says he supports the Senate pension bill and would sign it with the fiscal office attached.

Castle doctrine. The Senate gave final approval, 45-4, to a measure upholding the so-called castle doctrine. The bill would allow people to use deadly force in self-defense in their home or vehicle, or "anywhere the individual has a right to be."

The bill drew support from gun owners' groups, and opposition from major law enforcement officials including organizations representing district attorneys, police chiefs, and sheriffs.

Three of four votes against came from Philadelphia Democrats: Sens. Shirley Kitchen, Christine Tartaglione, and Vincent Hughes.

Sen. Anthony Hardy Williams (D., Phila.) said he supported the bill because he felt law-abiding constituents should be able to protect themselves against criminals who "shoot first and then rob you."

"Too many of my constituents are confronted with violence every day," Williams said. "We have to look at things in real-world terms."

The castle doctrine was tacked onto a bill tightening registration requirements for Megan's Law and must return to the House for approval.

Prison overcrowding. Also passing the Senate was a bill championed by Sen. Stewart J. Greenleaf (R., Montgomery) addressing Pennsylvania's swelling prison population.

The legislation would let someone who violates parole on a technical point or minor infraction be placed in a community-based or other alternative corrections facility rather than being sent back to state prison.

Another provision would let the state parole board release certain inmates to complete their prerelease programs outside prison. Currently, officials say, such programs can keep inmates in prison beyond the date when they would otherwise be eligible for release.

Rendell has said he would review the bill.

Port Authority. This bill grew out of the controversies plaguing the DRPA. The agency has come under fire for its spending and hiring practices, conflicts of interest, and lack of accountability and transparency. It has also been forced to end a long-standing practice of giving its employees free passage on its bridges and trains.

The bill, sponsored by Sen. John C. Rafferty Jr. (R., Montgomery), would require Senate confirmation of the governor's appointments to the DRPA board; prohibit board members and their businesses from profiting or benefiting from the agency; and give the governor veto power over the actions of the board of the bistate agency.

The bill goes to the House.

Urban blight. The Senate voted unanimously for a bill giving municipalities more tools to fight blight. The measure would allow cities to go after property owners' personal assets to pay for cleaning or fixing up properties adjudged a public nuisance or with serious code violations.

It also would allow municipalities to deny new permits to such property owners. The bill goes to Rendell's desk.