A blogger at "The New York Times" last week published information obtained from three leaked documents detailing Microsoft arguments to the US Federal Trade Commission (FTC) about the proposed Google purchase of DoubleClick. The FTC has subsequently approved the purchase.

The documents show that Microsoft created a supposedly independent company to fight the deal on competitive grounds, paid lobbyists and lawyers to pester the FTC, and, perhaps most interesting, illustrate how the software giant views how the combination of Google and DoubleClick would dominate online advertising.

According to the Microsoft documents, the merger of Google's and DoubleClick's online advertising efforts is a vertical one because the companies currently sell different kinds of ads and the result would be an "unbeatable market position."

"As a result of the acquisition, Google will serve--on a revenue basis--almost 78 percent of all non-search ads served to third-party Web pages," one of the Microsoft documents notes. "A merger of dominant firms in vertically related (or complimentary) markets can violate antitrust law. That is particularly true when the acquired party controls assets that competitors of the acquiring party have relied on to reach the market and that cannot be duplicated in a timely fashion once the assets are acquired by the dominant rival."

As highlighted by The Times, Microsoft recommended that the FTC reject the deal, but provided a list of possible conditions it could implement if the deal was to be approved. The FTC later approved the deal with no conditions in a 4-to-1 vote.

Google's DoubleClick purchase still has one major antitrust hurdle to overcome before it can be finalized. The European Union (EU) is also investigating the antitrust implications of this purchase and has proven much more aggressive than its US counterparts in protecting competition and consumers.