Sep 7, 2010 10:44 GMT  ·  By

Apple has spent roughly $1 million with search giant Google on AdWords in June, as did chip maker Intel, leaked internal documents reveal.

Considering the month of June is representative for Apple's average spending on ads with Google, the company therefore spends around $12 million on search-related ads every year.

Apple is just one of the 47 advertisers which reportedly spent over $1 million in June on Google's AdWords. These are small figures, though, given Apple’s stature.

For example, Google's biggest advertiser in June was AT&T, Apple's exclusive iPhone carrier in the U.S.

The operator spent some $8.08 million on AdWords for the month, according to the leaked documentation.

Other big spenders include Hungry Machine, which does business under the name Living Social, and Yellowpages.com. They spent $2.4 million, and $1.2 million respectively in the month of June.

The search-spending document obtained by Advertising Age acts as a revealing cross-section of the search giant’s business, offering a glimpse at one of the most least transparent areas of ad spending, the report notes.

Reportedly, the document is not a complete list of advertisers on Google. However, the accuracy of the data was verified by multiple sources with direct knowledge of spending levels, AdAge said.

"The primary tactic Google uses to increase ad budgets is to show them what others in their category are spending compared to what they're spending," said Kevin Ryan, CEO of Motivity Marketing, a search-advertising consultancy.

"We can't comment on these figures because we haven't seen the document in question or determined what these numbers represent," said Dennis Woodside, VP of Google Americas Operations.

"We're now looking into the possibility that someone improperly disclosed confidential information about our clients, and [we] will take all appropriate action."

Sill, even with so much cash poured in by big corporations, the top 10 advertisers listed in the document collectively accounted for just 5% of Google's U.S revenue in June, 2010, the report added.