Observers believe that Microsoft's antitrust charges will fail to convince regulators to block Google's proposed purchase of the online advertising company DoubleClick.

At the heart of the complaint is that Google's share of the search adverts placed on third-party websites, combined with DoubleClick's dominance of the business of serving up display adverts, would give the enlarged company a dominant position in the overall online advertising business.

Central to the complaint will be whether the search and display advertising businesses, until now separate, should be treated as a single market for regulatory purposes.

"It seems there is a clear distinction between Google's business and the business it is entering with the acquisition of DoubleClick," said Andrew Frank, an analyst at Gartner.

Some opponents, however, make the opposite argument. The search company has clearly stated an intention to integrate the two online markets closely together, according to Brad Smith, general counsel at Microsoft.

Announcing the proposed $3.1 billion (€2.3 billion) deal last Friday, the company said it would let advertisers manage their search and display campaigns using the same tools, making it easier to compare the effectiveness of their overall online advertising effort.

However, to the extent that the integration only happens at this level, the two markets could still be considered separate, with their own pricing dynamics.

Even if the two markets remain separate, though, combining a dominant position in each in a single company like this could put online publishers at risk, say critics.

According to Jim Cicconi, head of external and legislative affairs at AT&T, it would make any web company that depends on online advertising dependent on a single supplier.

In effect, Google would be able to influence the revenue lifeline of other internet companies, some of whom are its direct competitors. - ( Financial Times service )