* Second-quarter revenue $476 mln vs est $472.9 mln
* Adjusted profit $0.58/share vs est $0.55
* Shares down 6 pct after-market (Adds analyst and CEO comments, estimates, details, share move)
By Subrat Patnaik and Abhirup Roy
July 30 (Reuters) - Akamai Technologies Inc, which helps companies deliver internet content, reported a 26 percent rise in quarterly revenue, falling short of investor hopes that it would exceed its own forecast due to heavy World Cup traffic.
Shares of Akamai, whose customers include Microsoft Corp , Apple Inc and Nintendo Co, fell 6 percent to $57.05 in extended trading on Wednesday.
Strong first quarter results and excitement over the soccer World Cup suggested that the second-quarter results would likely be above Akamai's own forecast, Pacific Crest Securities analyst Chad Bartley told Reuters.
"It came in a couple of million below. I think people were disappointed in that," Bartley said.
Revenue rose to $476 million in the quarter ended June 30 from $378.1 million a year earlier, helped by increased demand for its media and security products.
Akamai had forecast second-quarter revenue of $464 million-$478 million.
"The revenue from the world cup is actually very small in the big scheme of things. It's noticed by a lot of people, so it is an important thing for us," Akamai Chief Executive Tom Leighton told Reuters.
Akamai said it delivered over 220 petabytes of World Cup traffic for 55 broadcasters in 80 countries, 10 times the amount of traffic it handled during the 2010 World Cup.
One petabyte is equal to about one million gigabytes.
The company forecast adjusted earnings in the current quarter of 55 cents-58 cents per share on revenue of $484 million-$496 million, largely above analysts' expectations.
Analysts on average were expecting a profit of 55 cents per share on revenue of $484.8 million, according to Thomson Reuters I/B/E/S.
Second-quarter net income rose to $72.9 million, or 40 cents per share, from $61.9 million, or 34 cents per share.
Excluding items, Akamai earned 58 cents per share.
Analysts on average had expected a profit of 55 cents per share on revenue of $472.9 million.
Shares of the Cambridge Massachusetts-based company closed at $60.73 on the Nasdaq on Wednesday.
(Additional reporting by Supantha Mukherjee; Editing by Rodney Joyce)