Fox Mobile/Jamba (part of News Corp. (NYSE: NWS)) CEO Lucy Hood has resigned this morning, we have learned through sources, and now confirmed by PR. Jamba COO Lee Fenton will be the interim CEO until they find a new replacement.

Updated: the company has now issued an official release, after stonewalling us for the last three hours on queries. The release says she wants to do more entrepreneurial ventures, but there has to be more than that: earlier this year she was appointed the CEO of the Jamster venture, in which News Corp. holds joint stake with Verisign. She has been with News Corp. for more than a decade, helped launch Fox Mobile Entertainment in 2005, and then this JV with Verisign. More in extended entry…

Staci adds: Yes, there is more to it although even this may not be all of it. According to one source familiar with the situation, the company is still very bullish on mobile but there’s a sense now that the operation probably needs to be run from Europe rather than LA. Most of the staff is based in Berlin and the business/opportunity is more Europe (and Asia) for now than in the U.S.. Hood traveled a great deal but was still based in the U.S. Fenton, who was hired as COO to lead worldwide operations, has the European know-how: he was director of consumer platforms for Vodafone (NYSE: VOD) prior to joining Jamba and before that was commercial director of Vivendi (EPA: VIV)-Vodafone JV Vizzavi. He’s held a variety of senior positions at other companies and could well be the top candidate to run Jamba on a permanent basis.

This source stressed that Hood is respected as an executive but her departure is likely to fuel some critics who didn’t see her as the right candidate to head the 600-plus employee JV, which was far bigger than Fox Mobile. 

Update: Some more details: Fenton is assuming Hood’s responsibilities but technically won’t be known as interim or acting CEO. I am told by another source in a position to know that he is a serious contender for the CEO job but there will be a search. Fenton was supposed to be LA-based when he was hired but that shifted. It’s uncertain now whether he will be based in Europe or U.S. during this transition.

The structure going forward has yet to be determined. As this source put it, “there probably will be some fallout; I don’t think any decisions have been made.” One possibility:  The Fox Mobile operations Hood led before the JV have been mostly integrated into Jamba but could wind up being more U.S.-centric or something different altogether.  Another possibility that could make sense: Pulling together the mobile efforts from the various Fox units—studios, FIM, etc.—into a Fox-centric mobile operation run from LA.

• Interview: Lucy Hood, CEO, Jamba
• CTIA: News Corp. Buying 51 Percent Of VeriSign’s Jamba For $187.5 Million
• Industry Moves: Lee Fenton Joins Jamba As COO; Leaves Vodafone