PATCO's proposals to extend commuter rail service along the Philadelphia waterfront could mean a new partnership with SEPTA, officials said today.

PATCO, which operates the 14-mile rail line between Lindenwold and Center City, wants to branch out in Philadelphia, extending service along Delaware Avenue and perhaps to City Hall. The agency is considering re-opening the long-closed Franklin Square Station at 6th and Race streets to serve as the hub of the new service.

Three proposed routes are under consideration, with a price tag of at least $1 billion. If federal approval and funding were forthcoming, completion of the lines might be 10 years off. PATCO officials said it might be possible for SEPTA to operate the service, if PATCO built it.

Two public open houses are scheduled to show the proposals to residents and seek suggestions. One is Tuesday at the Painted Bride Theater Cafe, 230 Vine St., and the other is next Thursday at Emanuel Evangelical Lutheran Church, 1001 S. 4th St. Each session is from 6 p.m. to 8 p.m.

Contact Paul Nussbaum at 215-854-4587 or pnussbaum@phillynews.com.