New deals in Asia boost Yahoo’s mobile search reach as the try to grab a bigger slice of the market for advertising on the small screen.

As we get caught up in the search ad machinations between Yahoo and Google in the United States, it’s easy to lose focus on international deals. Over the past year, Yahoo has been making deals with a number of wireless telecoms, and becoming the default search provider for their customers.

The latest set of agreements pulled in six more telecoms in Asia. Reuters cited David Ko, Asia managing director and vice president of Yahoo’s mobile division, on the latest round of deals.

These put Yahoo’s reach on mobiles to 600 million, Ko said. In countries where use of the wireless web and associated services exceeds that per-person of US subscribers, it’s easy to see the benefit. Yahoo gets more usage, more chances to display mobile ads, and more opportunities to make money from subscribers.

The only little setback we have seen for Yahoo on mobiles was the end of a one-year deal with Opera Software, which had offered Yahoo as the default search for its excellent mobile browsers. That agreement ended with Opera switching back to Google for its search.

If Yahoo keeps securing deals in Asia, they won’t miss Opera. Now they just need the monetization to reach or exceed expectations in order to help satisfy shareholders who are miffed over the loss of a deal with Microsoft to sell the company.