Shares fell 19% in after-hours trade.

Facing high inflation and receding consumer demand, new Chief Executive Officer Andy Jassy has raced to control costs across Amazon's vast array of businesses.

For months, the online retailer has slowed warehouse openings and refrained from filling some open positions. It announced it would shut down its virtual healthcare service by year end, and it is scaling back a long-touted effort to deliver goods via small autonomous sidewalk cars.

Its peers have seen few bright spots. In the retail sector, U.S. online sales are expected to rise at their slowest pace in years this holiday season. Results in the tech industry were just as poor this week for cloud-computing rivals Microsoft Corp. and Alphabet Inc.'s Google, adding to recession fears. U.S. consumer confidence did a U-turn in October.

In light of this, Amazon lost $2.9 billion in the third quarter, far below analysts' average estimate of a $2.2 billion profit, according to IBES data from Refinitiv.

In a statement, Jassy said, "There is obviously a lot happening in the macroeconomic environment, and we’ll balance our investments to be more streamlined without compromising our key long-term, strategic bets."

Amazon has sought higher revenue in all places. It raised fees for its fast-shipping club Prime up to an annual 43% in Europe this quarter. It imposed a fuel and inflation surcharge on some merchants, and for the first time it had not one, but two cornerstone sales events in a year: Prime Day in July, and the Prime Early Access Sale this month.

These efforts might not pay off. Amazon's net sales were $127.1 billion in the third quarter ended Sept. 30, little lower than analysts' expectations of $127.46 billion, according to IBES data from Refinitiv.

And for the holiday quarter, the world's biggest online retailer forecast net sales of between $140 billion and $148 billion. Analysts were expecting $155.15 billion.