In a move that would shake up the Mobile advertising world, BusinessWeek announced that Apple and Microsoft have been discussing a deal that would make Bing the iPhone’s default search engine. Currently, that honor is held by Google, which is run by mobile advertising company AdMob, Google’s recent $750 million dollar acquisition. Although users would still be allowed to switch their default back to Google, the coveted “default search engine”, would certainly result in a gain in market share.

In 2009, Google accounted for almost 88 billion searches or 67% of the global search market. Bing registered just 4.1 billion, but did grow 70% over Microsoft’s previous year with Live. Microsoft has a long way to go before it catches Google in the search market, but an iPhone move to Bing would be a large step in the engine’s uphill battle.