Microsoft has agreed to acquire advertising vendor AdECN for an undisclosed sum. 

AdECN operates on the same premise as a stock exchange, providing an open forum in which publishers can auction off advertising space to independent advertisers.

Microsoft said that it will let AdECN continue to operate as a separate entity, rather than assimilate the service into its web offerings, and will attempt to build it into a large open marketplace.

AdECN will remain in its offices in California and will operate as a subdivision of Microsoft's Online Services unit.

The decision to keep AdECN at a distance reflects a new and interesting strategy for Microsoft, according to Greg Sterling, founder and principal analyst at Sterling Market Intelligence. 

Sterling told vnunet.com that, rather than try to match Google move-for-move in the advertising arena, Microsoft is trying to remain somewhat neutral and foster an alternative market to Google's proposed DoubleClick network. 

"[Microsoft] characterised it as taking AdECN off the off the market so that it would not get gobbled up," he said.

"Microsoft is in a certain way positioning itself as the anti-Google, presenting Google as a monopoly. Microsoft wants to be the favourite partner, where there is openness and transparency."

Sterling suggested that AdECN will not be much of a threat to Google even with Microsoft's backing.

Google is likely to be more concerned with finalising the DoubleClick deal and getting the new network off the ground.