Google and EarthLink on Friday reached an agreement on the terms of the contract for the two companies to build a free, citywide wireless network in San Francisco.

The agreement, which followed about eight months of negotiations, must now be approved by the city Board of Supervisors, which expected to look closely at the proposed contract. Some members of the board have said publicly that they favor a city-owned network and have asked for a study to see if the alternative would be a better option.

Nevertheless, an EarthLink executive, in announcing the contract proposal, said in a statement that it "catapults San Francisco into a leadership position in wireless technology."

"The network ensures universal, affordable wireless broadband access for all San Franciscans, especially low-income and disadvantaged residents," Donald Berryman, president of the Internet service provider's municipal networks unit, said. The companies hope to begin construction this year.

The joint Google-EarthLink proposal was chosen last April over five other bids to build a Wi-Fi network that would blanket the city. Mayor Gavin Newsom had launched the wireless broadband initiative in order to provide free Internet access to poorer residents.

Google plans to provide the free Wi-Fi service, generating revenue through advertising. EarthLink would handle the faster, paid service, which would cost about $20 a month. Google, based in Mountain View, Calif., and EarthLink, based in Atlanta, plan to share the cost of building the network, which is estimated to be $8 million. The city would pay nothing, and receive fees for leasing city property, such as lampposts and power poles, for Wi-Fi antennas.