Zipcar Inc., a for-profit car rental service based in Cambridge, Mass., has replaced local nonprofit PhillyCarShare as the City of Philadelphia's rental car supplier, city and Zipcar officials said. Zipcar "had the lowest price," said Robert Fox, head of the city's Office of Fleet Management.

Philly Car Share bid $5.90 per hour and 9 cents per mile in its losing offer, said deputy executive director Clayton Lane. "We're proud to have partnered with the city," he said, "but it will only have a very modest impact on our business."

The city used about 6 to 10 cars a day from PhillyCarShare, and expects to use the same from Zipcar, said procurement commissioner Hugh Ortman. PhillyCarShare has about 500 cars in its local fleet; Zipcar has about 110. PhillyCarShare cost the city about $35,000 a year; Zipcar will cost an estimated $30,000, Ortman added.

Zipcar expects to be able to boost car use, said Zipcar President Mark Norman. He praised Philadelphia's bidding process as "transparent and open."

Earlier this year, city officials said Philadelphia had been able to get rid of 100 cars after contracting with PhillyCarShare for occasional use.

Norman said Zipcar has 110 cars in the Philadelphia area, and will boost the total if usage keeps rising.

Greylock Partners, of San Mateo, Calif., Benchmark Capital, of Menlo Park, Calif., AOL founder Steve Case's Revolution Living LLC, and other investors have put more than $35 million into Zipcar since 2003.