The Nutter administration says selling Philadelphia Gas Works could fetch even more money than predicted.

A new consultant's study estimates auctioning Philadelphia Gas Works could net the city between $400 and $800 million.  Selling the utility would mean PGW would no longer send the city $18 million dollars each year.

Budget Director Rebecca Rhynhart says even so, it's worth it to shore up Philadelphia's pensions.

"Once we contribute the money into the pension fund, the annual required contribution would go down by more than the $18 million in lost revenue.  The general fund is held harmless," she said.

It's unclear whether City Council will sign off on the sale. Unions are lobbying against it.

Mayor Nutter's spokesman Mark McDonald says it's a matter of dollars and cents.

"When we get to a point where we know 'x' millions of dollars are on the table, then council members and the mayor will be in a position to talk about whether we consummate that sale," he said.

Preliminary non-binding bids on PGW are due November 1. The deal could be final some time next year.