The system has already attracted some criticism, with rivals now urging regulators in the US to investigate whether iAd has constructed a "walled garden" to which third parties should be allowed access.
The company will sell, produce and host the advertisements, but will let developers keep 60% of the revenue generated by the ads, while Apple will keep 40%.
Apple is reported to have $60m (£40m) in bookings from interested parties, with car marque Nissan and financial group Citi named as launch advertisers. Unilever brands are also expected to be on the platform at launch, as are AT&T, Best Buy, and Chanel.
Apple plans to charge each advertiser a minimum of $1m (£671,000) when the platform rolls out in the next few months.
The figure accounts for nearly half the spend from mobile advertisers in the US for the second half of this year.
The new service is seen as a direct move to challenge any future moves into the mobile advertising sector by Research in Motion’s BlackBerry product range, or by Google’s burgeoning Android platform.
The system will launch today in the US and the UK in September. It is being sold by Quattro Wireless, the mobile advertising specialist acquired by Apple in January for $275m (£184m).
At the launch of iAds in San Francisco, Apple chief executive Steve Jobs, said: "It's all about helping our developers make some money with advertising.
"We think most mobile advertising really sucks. We thought we might be able to make some contributions."