SAN FRANCISCO, July 26 (Xinhua) -- U.S. e-commerce giant Amazon on Thursday reported its second-quarter profit topping 2 billion U.S. dollars, surpassing market expectations.

In a report on its financial results for the second quarter ending on June 30, Amazon said its net income increased to 2.5 billion dollars, compared with 197 million dollars in the same period last year.

On a per-share basis, Amazon registered earnings of 5.07 dollars, more than double Wall Street's estimate of 2.50 dollars.

The Seattle-based company said its net sales jumped 39 percent to hit 52.9 billion dollars in the period, compared with 38.0 billion dollars in the second quarter of 2017.

The online retailing giant's Amazon Web Services (AWS) cloud business is the key profit maker, up nearly 48.9 percent to 6.11 billion dollars in sales.

The operating income of Amazon rose to 3.0 billion dollars in the second quarter, a sharp growth from 628 million dollars in the same quarter of 2017, Amazon said.

As an e-commerce behemoth whose online sales account for almost half of the total in the United States, Amazon expects its revenue to grow to between 54 billion to 57.5 billion dollars in the third quarter, with a projected operating income of 1.4 billion dollars to 2.4 billion dollars.

Amazon CEO Jeff Bezos disclosed for the first time in April that his company has more than 100 million Prime Members worldwide who pay for its prime subscription services ranging from free shipping and delivery, video streaming, discounts for its Whole Foods products and other benefits.