AOL has sharpened its ad-targeting tools for the iPhone in a nod to the popularity of the Apple smartphones.

The Internet media company said on Wednesday that it has updated its advertising system, 

known as Platform-A, so marketers can send promotions to people while they’re surfing the Web on the iPhone.

When an iPhone user visits any of AOL’s sites or those of its partners, for example, the company will show that person a specially formatted banner ad or a marketer’s Web site on the iPhone.

The ad technology will be sold through the brand Third Screen Media, the mobile-advertising arm of Platform-A.

AOL’s Platform-A already has broad reach, but the company is surely tr

ying to become the de facto ad system on the smartphone. According to June statistics from ComScore, Platform-A is the top-ranked ad network, reaching 90 percent of the nearly 190 million Americans who are online. (The Yahoo Network was second, at 83 percent, followed by the Google Ad Network, at 81 percent, and Specific Media, at 78 percent.)

With these new Platform-A changes, AOL said it can deliver as many as 75 million ads to iPhones every month.