The CEO of aspiring mobile OS player Mozilla is to step down “later this year”, with the organisation today claiming that Gary Kovacs has “accomplished the goals and objectives he and the team set out to achieve” at the time of his appointment in October 2010.

There is no word yet on his replacement, although Mozilla said in a statement that a search will begin immediately. No exact leaving date has been set, with Mozilla keen to stress that Kovacs will “continue to provide vision and leadership as a member of our Board of Directors.” Meanwhile Mitchell Baker, chair of the Mozilla Foundation, is to become Executive Chair amid plans for her to take “deeper involvement in Mozilla’s daily activities.”

In other staff moves, Jay Sullivan, previously Senior Vice President (SVP) of Products, has been appointed Chief Operating Officer, while Li Gong has been appointed SVP, Mobile Devices (and will maintain his role as head of Asian operations).

Mozilla is the organisation behind the open-source desktop browser Firefox, and has recently made a major push into the mobile space. At Mobile World Congress in February Mozilla unveiled its mobile Firefox OS initiative, supported by 17 operators.

In a blog post today, Mozilla’s Chair Mitchell Baker talked up the role that Kovacs has played in moving Mozilla from the desktop browser world into the mobile ecosystem: “In 2010 we knew that we would need to change many things in order to be effective in the mobile computing environment: our technology, our expertise, our worldview, our focus. Gary’s leadership during this period has helped us build on the strong foundation to make these changes, and to bring that strength into the mobile environment. Gary has reinvigorated our focus on working with commercial partners, a trait that was central in Mozilla’s early life but less so during the Firefox desktop era.”

Watch an exclusive video interview with Kovacs – recorded at Mobile World Congress – here.