Uber's financials are improving: It lost $708 million on $3.4 billion in revenue in Q1

• Uber reported a loss of $708m in the first quarter, lower than the $991m it lost in Q4.
• Guatam Gupta, the start-up's head of finance, is leaving.

Another Uber executive is leaving, even as the privately held company is narrowing its losses.

Uber reported a loss of $708 million in the first quarter, narrower than the $991 million reported the previous quarter, Uber confirmed to CNBC. Revenue grew 18 percent on a sequential basis to $3.4 billion.

Travis Kalanick, chief executive officer of Uber Technologies Inc.

Qilai Shen | Bloomberg | Getty Images

"The narrowing of our losses in the first quarter puts us on a good trajectory towards profitability," Uber said in a statement to CNBC.

But Gautam Gupta, the start-up's head of finance, is leaving to join another San Francisco-based company.

"Gautam is a world-class financial talent," CEO Travis Kalanick said in an emailed statement to CNBC. "Over the last four years, he has been indispensible in helping build Uber from an idea into the business it is today. We couldn't have done it without him, and I will miss his energy, focus and infectious enthusiasm. All of us at Uber wish him well in this next challenge."

Gupta's departure comes as Uber has been without a chief financial officer since 2015. Uber has also lost high-profile executives like self-driving head Anthony Levandowski and president Jeff Jones.

The first quarter finances and Gupta's departure were reported earlier by The Wall Street Journal.

Correction: This article has been updated with the correct spelling of Gautam Gupta's name.