McAfee Inc , the No. 2 U.S. security software maker, reported quarterly revenue that missed Wall Street projections as sales to consumers grew at their slowest rate in almost two years.

The company's shares fell 4.5 percent as the revenue shortfall, which came in the wake of substantially stronger-than-expected earnings from bigger rival Symantec Corp , overshadowed better-than-expected profit.

McAfee on Thursday reported profit, excluding items, of 62 cents per share, in the third quarter ended September 30, above the average forecast of 60 cents, according to Thomson Reuters I/B/E/S.

Revenue rose 18 percent to $485 million, below the $487 million average analyst forecast.

Sales of McAfee's consumer software rose 8 percent from a year earlier to $177 million. It was the slowest rate of growth since the fourth quarter of 2007.

Its corporate business reported a 25 percent sales increase, posting quarterly revenue of $308 million.

Investors closely watch sales of consumer software because analysts say that such products are more profitable than programs for businesses. The company does not disclose the profits of each division.

McAfee also said that it has agreed to pay No. 2 PC maker Dell Inc to recommend its security software to its customers worldwide for at least the next two years. McAfee has the right to extend for a third year.

This relationship is very profitable for McAfee, said Chief Executive Dave DeWalt, who has negotiated deals with other PC makers that have boosted sales of consumer software in previous quarters.

Those sales grew at a year-on-year rate of 13 percent in the second quarter and 12 percent in the first quarter.

The company forecast that it will report fourth-quarter profit, excluding items, of 61 to 65 cents per share on revenue of $505 million to $525 million. Analysts expect McAfee to post profit of 63 cents per share on revenue of $507 million.

Net income fell 25 percent to $37 million, or 23 cents per share, from $49 million, or 31 cents, a year earlier.

McAfee shares fell 4.5 percent to $41.80 from their New York Stock Exchange close of $43.75.

(Reporting by Jim Finkle, editing by Leslie Gevirtz)