Inc posted a 68 percent surge in net income on Thursday that blew past analyst estimates, but its revenue and income outlook failed to impress Wall Street and its shares fell 5 percent.

The world's largest online retailer reported net income for the first quarter of $299 million, or 66 cents per share, up from $177 million, or 41 cents per share, a year earlier.

Analysts, on average, had been expecting earnings of 61 cents per share, according to Thomson Reuters I/B/E/S.

Revenue jumped 46 percent to $7.13 billion -- above the $6.87 billion expected by analysts.

Amazon, whose profit surged 71 percent during its holiday quarter, has been on a roll since last year, its sales outpacing both the broader e-commerce and brick-and-mortar retail markets.

Looking ahead, Seattle-based Amazon estimated operating profit in its second quarter of $220 million to $320 million on revenue of $6.1 billion to $6.7 billion.

Analysts, on average, have been expecting an operating profit of $327.8 million on revenue of $6.43 billion in the second quarter.

Amazon shares fell 5 percent in extended trade to $142.56 after closing at $150.09 on Nasdaq.

(Reporting by Alexandria Sage; Editing by Richard Chang)