Splunk Inc. climbed in late trading Thursday after the maker of software that helps businesses analyze Web data reported a narrower fiscal second-quarter loss than analysts estimated and raised its full-year sales forecast.

The shares of San Francisco-based Splunk gained as much as 16 percent to $35.39 in extended trading after earlier closing at $30.50 in New York.

Splunk has surged 79 percent since selling shares at $17 apiece in an initial public offering in April. The company has won business from customers including Zynga Inc., Bank of America Corp. and Autodesk Inc., which are looking for new ways to monitor and analyze the vast amounts of data being created by Web services and mobile devices.

Revenue for the 2013 fiscal year ending in January will be $183 million to $186 million, Splunk said in a statement, higher than the company’s prior forecast of $174 million to $177 million.

For the second quarter, which ended July 31, Splunk reported a net loss of $4.58 million, or 5 cents a share, compared with a loss of $3.91 million, or 20 cents, a year earlier. The loss excluding certain items was 1 cent a share, smaller than analysts’ average estimate for a 3-cent loss, according to data compiled by Bloomberg.