AOL's Advertising.com will partner with general trading firm Mitsui and Co. to operate a joint performance-based online ad network in Japan - the first joint venture for the online ad company.

Advertising.com hasn't yet decided whether it will offer pre-roll or in-stream video advertising, according to Dave Jacobs, VP of corporate development, but "definitely wants to understand [the Japanes market] better" before deciding, ClickZ reports. The partnership marks Advertising.com's first move outside of the U.S., Canada, and Europe.

Also still uncertain is whether the network will be a "blind network" or advertisers will be made privy to which publisher sites their ads might run on. "We recognize site disclosure is always a sensitive topic," Jacobs told ClickZ.

Mitsui in 2004 began using FindWhat.com's private-label service for a now-defunct pay-per-click keyword-based ad network in Japan called LISTOP. The company also has invested in online firms such as LinkShare and RSS feed platform provider Feedster.