• by Gavin O'Malley  @mp_gavin, October 5, 2009

MySpace on Monday named Mark Rosenbaum as its new chief financial officer, effective immediately. Reporting directly to MySpace CEO Owen Van Natta, Rosenbaum will oversee all finance and accounting operations at the social network.

Previously, Rosenbaum served as a consultant to MGM, advising on business intelligence and financial management system implementation.

Despite the stratospheric rise of rival Facebook, MySpace is not going down without a fight, and continues to hold its own in several key areas.

Calling MySpace "one of the largest operations on the Internet," Rosenbaum pumped it up into "a world class platform."

MySpace Music, a joint venture in which top music labels have an equity stake, has grown 1,000% over the past year, and 200% annually since its launch, according to Van Natta.

In late August, the News Corp. unit acquired popular music recommendation startup iLike -- reportedly for about $20 million -- to bolster the service, and the site's broader infrastructure.

Also this summer, Van Natta brought in consultancy firm Media Link -- where Wenda Harris Millard has served as president since April -- to advise MySpace on its ad strategy.

Word of the partnership was accompanied by news that MySpace's ad sales head Jeff Berman was leaving the company. Also with Berman, MySpace has lost a number of senior employees over the past year.

Other recent departures include Heidi Browning, SVP of insights and planning at MySpace; SVP of product management Tom Andrus; MySpace international head Travis Katz; and MySpace Music SVP of strategy and global marketing Jamie Kantrowitz.

During the first week of September, Facebook captured nearly 58% of visits in the social networking custom category, according to research firm Hitwise. MySpace -- which was the top dog in social networking as recently as May -- trailed Facebook significantly with a mere 31% share of the market.

Prior to MGM, Rosenbaum held the position of SVP of corporate finance at Gemstar-TV Guide -- formerly a News Corp. company -- and served as CFO of the TVGuide.com and TV Guide Mobile units.