Demand Media Inc. late Thursday said that Chief Financial Officer Charles Hilliard was leaving and would be replaced by Mel Tang, the online media company’s treasurer. The change is effective Aug. 16.

Tang, 37, also serves as senior vice president of finance at the company, which contracts with freelance writers to provide content for advertiser-supported special-interest web sites that include eHow and LiveStrong.

Prior to joining Demand Media in 2006, Tang was a director in the media investment banking group at UBS, worked at venture capital firm Prime Ventures, and was an investment banking analyst at Donaldson Lufkin & Jenrette.

Hilliard, 48, holds the position of president and will continue to have a relationship with the Santa Monica company as a special adviser to the board. He joined the company in 2007, and was instrumental in efforts to take it public in January of last year.

“When I brought Charles in, the idea was for him to get us public and set up an infrastructure that would allow us to become a successful public company and he did a great job with that,” said Chief Executive Richard Rosenblatt in a statement.

The company also reaffirmed its financial guidance for the current quarter and fiscal 2012.

Shares earlier closed up 40 cents, or 4 percent, to $10.32 on the New York Stock Exchange.