Amazon.com Inc. (Nasdaq: AMZN), the world’s largest online retailer, reported revenue that missed analysts’ estimates and posted the first quarterly net loss since 2003, hurt by higher expenses and its investment in LivingSocial.com.

Shares fell in extended trading after the company reported a third-quarter net loss of $274 million, or 60 cents a share, compared with net income of $63 million, or 14 cents, a year earlier. Sales rose 27 percent to $13.8 billion, Seattle-based Amazon said in a statement Thursday. That compares with the $13.9 billion average analyst projection compiled by Bloomberg.

Chief Executive Officer Jeff Bezos is opening 19 fulfillment centers worldwide to offer speedier delivery to customers during the holiday shopping season, contributing to a 28 percent increase in operating expenses. Amazon also boosted spending on technology and content by 55 percent as it added video streaming and released new Kindles.

“Amazon is spending a lot to gain market share,” said Sucharita Mulpuru, an analyst at Forrester Research Inc. “They’re obviously, as they call it, investing in the business — everyone else would call it losing money.”

Amazon shares slipped 1.3 percent to $220 in extended trading following the report. Before the announcement, the stock had lost 2.4 percent to $222.92 at yesterday’s close in New York, and has gained 29 percent so far this year.

LivingSocial Loss

Amazon’s third-quarter loss includes a charge of $169 million, or 37 cents a share, related to its stake in daily-deal website LivingSocial, which lost value as consumers and retailers soured on Internet coupons. Amazon invested $175 million in the coupon service in 2010, which means it has since lost 95 percent of its value, data compiled by Bloomberg show.

“Daily deals has been struggling,” said Daniel Kurnos, an analyst at Benchmark Co. in Boca Raton, Florida. “LivingSocial is going to need to re-accelerate their marketing expenses to keep the status quo.”

Excluding the impact of LivingSocial, Amazon had a loss of 23 cents, exceeding the 8-cent loss predicted by analysts, according to data compiled by Bloomberg. On an operating basis, the third-quarter loss was $28 million, less than the average analysts’ estimate for a $42.1 million loss.

Fourth-quarter operating income will range from a loss of $490 million to a profit of $310 million, compared with analysts’ projections for $354.1 million in profit. Sales will be $20.3 billion to $22.8 billion, while the average estimate is $22.8 billion.

Broad Investment

Amazon is investing across the company to support a larger volume of products sold on its site, Tom Szkutak, Amazon’s chief financial officer, said on a call. That includes technology, such as the new Kindle devices it rolled out last month, and content deals — like the one with pay-television channel Epix in September — for its streaming video service. Fulfillment and server maintenance for its Web services business are also factors, he said.

“Those fulfillment centers don’t have the productivity until sometime in the future,” he said. “Two of the primary drivers of both are capacity-related. We’re adding a lot of infrastructure-related costs — our fast-growing web services business, also to support the growth of our retail business.”

Amazon has reported an operating margin of less than 2 percent for the last five quarters, according to data compiled by Bloomberg. The company is valued at 254.5 times earnings, the highest of any in the Standard and Poor’s 500 Index, the data show.

“Amazon has the lowest operating margin and the highest valuation in our technology company coverage,” Colin Gillis, an analyst at BGC Partners LP in New York, said in a note to clients yesterday. “The company is not likely to achieve material leverage off its revenue growth as costs associated with investments into its digital platforms build.”

Kindle Push

Amazon unveiled a line of bigger and faster Kindles that range in price from a $69 ad-supported reader to the $599 top- of-the-line Kindle Fire HD tablet. The new devices are competing in a tablet market expected to reach $63.2 billion this year, according to researcher NPD DisplaySearch.

The e-commerce company is facing escalating competition from competing devices. Google Inc. announced the Nexus 7 in June, Apple Inc. unveiled the iPad mini, a tablet with a 7.9- inch screen, this week, and Microsoft Corp. began selling its Surface tablet today.