Shares of Akamai Technologies Inc., which helps speed Internet-data delivery for customers such as Apple Inc. and Sony Corp., soared as much as 19 percent in late trading Wednesday after the company beat analysts’ estimates for fourth-quarter profit.

Leaving out one-time items, profit was 55 cents a share, topping the 51-cent average estimate of analysts compiled by Bloomberg. Sales jumped 15 percent to $436 million, surpassing the $423 million analysts projected.

The company also forecast first-quarter profit and sales ahead of analysts’ estimates, allaying investors’ concern that Apple may build its own content-delivery network, reducing its reliance on Akamai. The Cambridge, Massachusetts-based company is growing across all its business lines and geographic divisions, it said.

Profit will be 51 cents to 55 cents a share in the period ending in March, Akamai said on a conference call today, compared with analysts’ 49-cent estimate. The company’s sales forecast of $426 million to $442 million compared with the average estimate of $413 million.

At 6:30 p.m. in New York, the company's shares were up 17 percent at $55.50, after trading as high as $56.35. The stock gained 2 percent in regular trading.