Yahoo Inc's head of North American revenue and market development is leaving the company to join private online content start-up Demand Media, becoming the latest executive to depart the Web giant's ranks.

Demand Media said Joanne Bradford will join the company as its first chief revenue officer to oversee advertising sales and the company's recently launched online content services business.

The departure of Bradford, a former executive at Microsoft Corp, comes as Yahoo is in the midst of a turnaround effort led by Chief Executive Officer Carol Bartz. Since Bartz took the reins in January 2009, Yahoo has cut headcount and divested certain products and assets to reduce costs and focus on its core online media and entertainment business.

In July, Bartz struck a 10-year deal with Microsoft that lets the software company provide the back-end technology that powers Yahoo's Web search capabilities.

Bradford joined Yahoo in September 2008.

Yahoo confirmed a report on tech blog AllThingsDigital that Bradford decided to leave Yahoo, saying she would be working with the team over the coming weeks to enable a smooth transition.

In an interview with Reuters on Monday, Demand Media CEO and co-founder Richard Rosenblatt said Bradford will help the company aggressively expand its focus on ad sales as well as a new service in which Demand Media sells companies specialized content and social media tools for their web sites.

Almost as easily as you can deliver ads, we can now deliver content, social media and ads, said Rosenblatt.

Santa Monica, California-based Demand Media produces online articles and videos about a variety of subjects by employing an army of freelance writers and editors. The company has raised $355 million in funding from investors, including Oak investment Partners and Goldman Sachs, according to its website.

Rosenblatt said Demand Media generates roughly $200 million in annual revenue.

(Reporting by Alexei Oreskovic, editing by Leslie Gevirtz and Carol Bishopric)