According to ClickZ, the search engine will launch the tool within the next two weeks.

 

It will enable advertising networks and publishes to offer their unsold inventory to advertisers, something that may be of use to companies conducting a managed pay per click campaign.

 

The news source said a person familiar with the plans made by Google's DoubleClick unit expects the launch to take place by the end of the month.

 

However, the company would not comment on the reports.

 

Companies that are selling ad space through the exchange will be guaranteed to receive the highest price bid above a set reserve - which they can specify.

 

ClickZ said that it will also offer buyers the opportunity to purchase a large amount of display advertising space "at bargain rates", but it is not yet known the volume that will be available at the time of launch.

 

Elsewhere in the online advertising sector, it was recently suggested that Microsoft may introduce online advertising to captcha systems.

 

The firm has filed a patent that would enable it to use the boxes - which display a randomly-generated word or phrase that internet users have to enter for security purposes - for marketing purposes.