Uber's Chief Financial Officer Brent Callinicos is stepping down from his position after overseeing the ride-hailing company the last two years.
Company CEO Travis Kalanick announced the news of Callinicos' departure in an email to investors, according to a letter obtained by The Wall Street Journal.
Callinicos, who joined the company in 2013 after six years at Google, will remain on board temporarily as an advisor, according to Kalanick's email.
The shocking departure comes as Uber is widely expected to be preparing for an initial public offering.
"Almost two years ago, I brought on one of the great financial operators in Silicon Valley as our CFO," Kalanick said in his email on Monday. "Though two years sounds short, Uber was a much smaller startup then -- about one-tenth the size we are today. Brent has provided critical leadership to take Uber to the next level as we matured as a company."
Callinicos helped the San Francisco-based startup company become the second-highest valued venture-backed company in the world today, which is now valued at $41.2 billion. The only company with a higher valuation is smartphone-maker Xiaomi, which has a valuation of $46 billion.
It seems Callinicos is leaving his job to spend more quality time with his wife and daughter.
"Brent has done a wonderful job here at Uber but has decided that it is time for his next journey, one where his wife and daughter take the front seat," Kalanick said in his email.
Callinicos confirmed those statements in his own e-mail on Monday.
"After 26 years of nonstop work since MBA School, I am going to step back and spend some time with my family and let someone else take this amazing company to the next level as CFO," he said, according to the Journal. "My daughter is in middle school; my wife has been supportively waiting to spend time with me for 28 years. I made a promise to both of them that I would be taking a long break at this stage of life."
During the past year, Uber has raised more than $2.4 billion, including the most recent round of $1.2 billion back in December. The follow month, Uber received a round of $1.6 billion in debt financing from management clients at Goldman Sachs.
Callinicos also spent 14 years working at Microsoft before joining Google back in 2007.