The fact that Microsoft is eager to challenge Google's internet advertising empire is hardly new. But an article in today's New York Times may be the official declaration of war from the software maker, which has selected aQuantive boss Brian McAndrews as its general in charge of waging the Google campaign.

While Google has a big lead in online advertising, a field that is relatively new to Microsoft, McAndrews is seen as the right man to challenge the search giant. And it's in the area of search where McAndrews is planning to strike. By proposing a system known as "conversion attribution," McAndrews believes he will be able to unseat Google.

"Google gets all the credit, and in fact, you might have just gone to Google to type in the URL," McAndrews told The New York Times.

In a nutshell, conversion attribution aims to deemphasize the importance placed on search by crediting the ads and webpages consumers view along the way to a purchase while putting less value on the initial search.

According to McAndrews, his key weapon in the fight against Google will be tracking technology developed by Atlas, a division of aQuantive. Although DoubleClick has similar technology, Google has yet to close its deal for the company because of privacy concerns. Yesterday, it was revealed that Microsoft may have played a role in delaying Google's efforts to close the deal by lobbying media outlets to question the privacy implications of Google's $3.1 billion DoubleClick purchase.