Mobile phone giant Nokia is to lose its second high-profile executive in less than a week.
Anssi Vanjoki, the head of Nokia's mobile business, resigned from a job that he began in July 2010.
His announcement follows Friday's appointment of Microsoft's Stephen Elop as the firm's new chief executive.
Mr Elop - the first non-Finn to head Nokia - will replace Olli-Pekka Kallasvuo, a lifelong employee who had been chief executive since 2006.
"I felt the time has come to seek new opportunities in my life," said Mr Vanjoki in a statement.
"At the same time, I am 100% committed to doing my best for Nokia until my very last working day."
Mr Vanjoki took up his job as executive vice president and general manager of the firm's mobile solutions division in July this year.
On his second day in the job he wrote a blog post titled The fightback starts now, vowing to bolster Nokia's smartphone efforts.
"It's my aim to ensure Nokia stays as the market and intellectual leader in creating the digital world," he wrote. "I'm under no illusions; it's no small task."
Despite being the world's biggest smartphone seller, Nokia has been losing the publicity battle with Google's Android operating system and Apple's iPhone.
Both are increasing their market share.
"I am committed, perhaps even obsessed, with getting Nokia back to being number one in high-end devices," wrote Mr Vanjoki at the time.
His strategy was based around the Symbian operating system and MeeGo, a joint venture between Nokia and Intel.
"Achieving this will require performance and efforts over and above the norm. This is a role I've personally been preparing for over the last 20 years."
Mr Vanjoki will now serve a notice period of six months before departing.
Analysts at CCS Insight said it was an "end of an era" and could signal further management changes.
On 10 September, the firm announced that it had appointed Microsoft business manager Mr Elopas its new CEO.
Mr Elop said his job was to "take the organisation through a period of disruption".
He will take up his new position at Nokia on 21 September.
The announcements come ahead of Nokia World, the firm's annual conference, which begins on the 14 September in London.
Source BBC NEWS