Zipcar Inc., the world’s largest car-sharing company, plans to announce Wednesday a partnership with Zimride, a fast-growing online carpooling service that uses social networking tools like Facebook Inc. to match potential riders and drivers on university campuses or at companies like Wal-Mart.

The partnership — being launched first at Stanford University — means carpoolers can share rides, even if they don’t own a car, using Zipcar’s hourly rental system. Car-sharing companies allow drivers to rent cars by the hour from locations close to their homes. 

When reserving a car on Zipcar, members will be able to automatically post the date, time and destination of their rental onto the Zimride Stanford University Web site. Then Zimride finds and notifies users looking for a ride. Zimride’s users also will be prompted to consider booking a Zipcar for their trip.

Zipcar declined to provide financial details on the partnership.

In recent years, online carpooling services such as Goloco.org and Pickuppal.com, which use social networking to link drivers and riders, have sprung up, but significant user growth has proved elusive.

 

In 2007, Zimride launched as the first online carpooling service to integrate a Facebook application — free software programs that Facebook members can use — to arrange ride-sharing within specific communities like universities or companies. Zimride could then use the social-networking site to show potential riders and drivers the people who might be riding with them.