The subsidies Uber grants its drivers was the main reason for the loss, finance head Gautam Gupta told investors in a quarterly conference call, Bloomberg said, citing sources. (http://bloom.bg/2bDGGI4)

Uber, whose investors include Goldman Sachs Group Inc and Amazon.com Inc Chief Executive Jeff Bezos, could not immediately be reached for comment.

The company lost about $520 million in the first quarter of the year and another $750 million in the second quarter, Bloomberg said.

Uber, which is now valued at roughly $69 billion, lost at least $2 billion in 2015, the report said.

The company's net revenue increased to about $1.1 billion in the second quarter from $960 million in the first quarter, while bookings rose to more than $5 billion from more than $3.8 billion in the prior quarter, Bloomberg said.

(Reporting by Supantha Mukherjee in Bengaluru; Editing by Savio D'Souza)