Officials in Pennsylvania are running up a growing taxpayer-funded tab to encourage the use of natural gas.

Bills pending in the Legislature could deliver hundreds of millions of dollars in subsidies over a decade. That's on top of the tens of millions of dollars that Gov. Tom Corbett has already summoned to help fund a processing project, pipeline construction, scores of natural gas vehicles and about a dozen fueling stations.

Plus, lawmakers last year approved a tax break possibly in excess of $1 billion over 25 years for any company that builds a multibillion-dollar petrochemical refinery.

Corbett aide Patrick Henderson couldn't say how much money the governor will ultimately spend to encourage natural gas use.

But Henderson defends the money as spurring economic development or diversifying vehicle fuel sources.