Microsoft Advertising launched its Canadian division last night at an exclusive party promoting its online ad network.

Jodi Kasten, director of sales for Microsoft’s advertiser and publisher solutions group, formally announced the Canadian launch of Microsoft’s ad network DrivePM, which connects advertisers to online publishers.

The service uses ComScore rankings to offer advertisers “the top 40 sites in Canada and the top 250 sites in the United States,” Kasten told attendees from the agency and marketing community in a brief address.

Microsoft acquired the DrivePM property when it bought digital marketing company aQuantive in May 2007.

Kasten also mentioned that Microsoft Advertising was the exclusive vendor of display advertising on Facebook. The social networking site, in which Microsoft has a small equity stake, recently became the world’s most popular online social network. According to online measurement company ComScore, Facebook is the third most visited website in Canada and recorded more unique visitors worldwide in May than its longtime rival MySpace.

Last night’s event marked Microsoft’s first steps into the Canadian ad market. DrivePM and Facebook ad sales are the only services currently on offer. Other products and services, such as the Atlas suite of publisher tools, will be unveiled as the Canadian team grows. The company currently has fewer than 15 staff.

“As we build and grow the team, we will have more dedication and focus on the technology and the infrastructure,” said Kasten.

Ad sales for other Microsoft properties, such as Sympatico/MSN, Hotmail and MSN Messenger, are handled by Bell Canada, Microsoft’s five-year partner in running the Sympatico/MSN portal. That contract, however, is in its final year and the relationship is currently being renegotiated.

The launch party took place at upscale Toronto restaurant Kultura, and featured celebrity DJ Samantha Ronson.