Google, the internet search group, and Earthlink, the internet service provider, on Wednesday drew closer to covering the city of San Francisco with a wireless broadband network, after a city panel selected the companies as the preferred providers for the project.

Google and Earthlink will now enter final negotiations with the city, which hopes to bypass traditional broadband providers to offer its 700,000 residents direct connection to the internet. The Google-Earthlink joint bid was one of six proposals under consideration.

The Google-Earthlink proposal endorsed by the city on Wednesday would see the companies offering a tiered payment system, including an Earthlink service that allows paying users to connect at significantly higher speeds than those who connect to a free service supplied by Google, which will be paid for by online advertising.

The bid to blanket cover San Francisco with cheap and ubiquitous internet access is part of a broader move towards municipal wireless networks by big US cities.

Philadelphia became the first major US city to begin construction of a citywide wireless network when it inked a deal with Earthlink earlier this year.

Other big cities, such as Chicago, Boston and Austin, Texas, have announced their own wireless network plans.

Google?s decision last year to offer San Francisco a free citywide wireless network attracted a lot of attention and sparked a wave of interest in free networks among smaller US cities.

Experts have warned, however, that the free wireless model remains unproven, and may not offer the best solution for smaller cities and towns addressing the ?digital divide? to promote economic development.

Google, Earthlink and the San Francisco mayor?s officer could not be reached for comment on Wednesday.