Dell Inc posted quarterly revenue slightly below expectations and said sales for the present quarter would be flat, sending its shares down 4.9 percent in after-hours trading.

The company said it was revising its full-year revenue growth outlook to 1 percent to 5 percent from its previous range of 5 percent to 9 percent.

The world's No. 2 PC maker, which in May had expected strong government spending and a good back-to-school season, recorded sales of $15.7 billion in its fiscal second quarter.

Analysts had on average predicted revenue of 15.76 billion, according to Thomson Reuters I/B/E/S.

The company founded by Michael Dell has consistently beaten Wall Street expectations this year, a result of expanding its footprint in higher-margin businesses such as servers, storage and computer services. But industry executives warn that corporate and government spending may have begun to wane on fears of a second-half economic growth slowdown, while a high jobless rate pressures consumer income.