Shares of online retail titan Amazon.com surged on Tuesday after the company reported that quarterly profit sank at the end of last year but its margins were better than expected.

The Seattle, Washington-based company reported a profit of $97 million on sales of $21.27 billion in the fiscal quarter that ended on December 31.

Sales were up 22 percent from the same period a year earlier, but profit was 45 percent less by comparison, according to the earnings report.

The earnings figures missed Wall Street forecasts, but a gross margin topping 24 percent outshined expectations regarding the share of revenue staying in the company coffers after costs.

Amazon.com shares climbed more than eight percent to $282.51 in after-market trading on the Nasdaq.

"We're now seeing the transition we've been expecting," said Amazon.com chief executive Jeff Bezos.

"After 5 years, eBooks is a multi-billion dollar category for us and growing fast -- up approximately 70 percent last year," he continued.

"In contrast, our physical book sales experienced the lowest December growth rate in our 17 years as a book seller, up just 5 percent."

Source: AFP