As relations between Apple and Google grow strained, rumors have swirled that Apple and Microsoft have discussed making Microsoft’s Bing the iPhone’s default search engine.

Businessweek on Friday offered more evidence of a deal in the form of an analyst note that said: “Though Microsoft did not confirm or deny any chatters on the likelihood of Microsoft wining Apple search deal for iPhone, [Microsoft executive] Mr. Apter told us that for right economics Microsoft would like to win the Apple search deal.”

The note, which came from Collins Stewart analyst Sandeep Aggarwal, also commented: “In our view, Apple search deal can be strategically very significant win for Microsoft not only because of Google and Apple’s history of working together but also because Microsoft has been lagging behind in terms of making in roads on fast growing mobile Internet market.”

And according to The Business Insider, search on the iPhone brings Apple US$100 million a year from Google as part of a revenue-sharing deal, making it less likely Apple would want to develop its own search engine. The publication cited “a source familiar with Apple's operations.”