Early reports have proven true: yesterday AOL officially acquired ad network Quigo.

Quigo offers ad buyers contextual matching along the same vein as Google AdSense or Yahoo's Publisher Network. The firm also permits publishers to sell their own inventory.

This is the fourth ad network AOL has purchased in 2007. Quigo joins TACODA, ADTECH AG and Third Screen Media.

Recent months also witnessed the development of AOL's in-house display advertising platform, Platform A.

Earlier this year Quigo signed a deal to have contextual ads, served through its AdSonar platform, placed on Time-Warner sites such as EW.com and SI.com.