T-Mobile USA is to deploy an integrated 3G / Wi-Fi network to compete with the new high-speed networks being built by its larger US rivals.

C-NET reports that T-Mobile will launch its 3G network this year – the last US mobile operator to do so – but hopes that by combining the network with Wi-Fi hotspots it will be able to deliver customers high-speed services quicker than Verizon Wireless, AT&T and Sprint Nextel, which have all yet to launch their so-called “4G” networks.

According to Joe Sims, T-Mobile USA’s vice president and general manager of broadband products and services, the operator will have its new network up and running in 80% of the top 20 US markets by the end of the year using spectrum won in the recent US government auction. Sim says this network will be able to seamlessly integrate with T-Mobile 9,000 public Wi-Fi hotspots in the US.

The operator already has a range of Wi-Fi-enabled handsets in the marketplace following the launch of its Hotspot @ Home service last year. It announced at the CTIA Wireless earlier this month that it will also become the first operator to launch the new Wi-Fi-enabled BlackBerry Pearl 8120.