Amazon.com Inc reported a big decline in quarterly profit Tuesday, while revenue surged, as the largest Internet retailer spent heavily on expansion and new ventures.

Amazon said fourth-quarter net income was $177 million, or 38 cents per share, down from $416 million, or 91 cents per share, a year earlier.

Revenue came in at $17.43 billion, up 35 percent from the fourth-quarter of 2010.

Amazon shares dropped more than 9 percent in after-hours trading following the results.

(Reporting By Alistair Barr; Editing by Richard Chang)