On the wired Internet, there’s little question about which browser is the leader, with Microsoft’s Internet Explorer the hands-down favorite. Not so on the mobile Internet, where there is a lot more fragmentation.

Still, it will surprise no one that Nokia’s mobile phone browser is the world leader. AdMob, the mobile advertising company, said in its most recent Mobile Metrics Report that Nokia’s browser was used by 34% of the phones accessing ads in AdMob’s network in July.

Running a close second to Nokia’s browser was the mobile browser developed by Openwave, which garnered a 29% share of ad views, AdMob said. Traffic from Motorola handsets was more than half of Openwave’s usage. Access’s NetFront browser, which is used by Sony Ericsson, was the third most widely used browser with a 12% share.

AdMob also said its mobile ad network saw an 18% increase globally in traffic in July, while U.S. usage climbed 5.8%.