For quite some time, Android has been gaining on Apple’s mobile operating system, looking more and more like it would become a favorite among advertisers.  Millennial Media has determined that Android’s growth slowed a bit in June, however, while Apple saw some impressive increases.

According to Millennial Media’s latest Mobile Mix report, "Apple ad requests increased 36% month-over-month; iPad ad requests grew 206% month-over-month."  Which is quite impressive, particularly considering the problems that surrounded the iPhone 4’s launch.

Android ad requests, meanwhile, grew just 23 percent in the same period, which is fine, but appears a little weak in comparison.  And that number could signal something of a falloff considering that ad requests have grown 439 percent since January.

As for how the situation looks if you take a step back from the stats concerning ad requests, Millennial Media stated, "Apple OS remained the leading Smartphone OS on our network in June with a 56% share of impressions and an 8% growth month-over-month."

Apple would perhaps do well to press its advantage and take the necessary steps to resolve all the iPhone 4 complaints, then.  Android devices come out on a regular basis; it’ll be quite some time before another iPhone surfaces to give Apple’s operating system an additional boost.

Stay tuned – we’ll be sure to report whatever Apple announces at its iPhone 4-centric press conference tomorrow.