Shares of Palo Alto Networks Inc. fell to their lowest level since the company's market debut after reporting fiscal first-quarter sales that failed to meet analysts’ most bullish estimates, a sign of lofty projections for growth at the maker of firewalls and other security technologies.

Shares of Santa Clara, California-based Palo Alto were down 4.3 percent at $49.11 at midmorning, after earlier trading at $48.50, the lowest intraday price since the company’s July initial public offering. Through Thursday, the stock had gained 22 percent since the IPO, which was priced at $42 a piece..

Sales during the three months that ended in October rose 50 percent to $85.9 million, the company said in a statement Thursday. While that was more than than the average prediction for $83.8 million, the highest estimate was $87.3 million, according to data compiled by Bloomberg. Profit before certain costs was 4 cents a share, higher than analysts’ projection of 3 cents a share.

Palo Alto, whose technologies are a combination of hardware and software, is benefiting as companies seek to defend against sophisticated hacking attacks that traditional security technologies have had difficulty stopping. The company is carving out a niche in an industry dominated by large rivals such as Cisco Systems Inc. and Juniper Networks Inc.

“The expectations for investors are pretty high for Palo Alto,” said Daniel Ives, an analyst at FBR Capital Markets & Co. in New York. “This company has been kind of put in a different sphere in terms of how investors view it.”

Ives has a market perform rating on the stock, equivalent to neutral. The net loss was $3.52 million, or 5 cents a share, compared with net income of $4.12 million a year earlier.

Second-Quarter Outlook

For the second quarter, profit before certain costs will be 4 cents a share, Steffan Tomlinson, Palo Alto’s chief financial officer, said on a conference call Thursday. That forecast is in line with the average estimate of analysts. Sales will be $90 million to $94 million, he said, compared with analysts’ projection for $90.7 million.

The rise in advanced threats and increased regulatory requirements around data protection is helping drive sales. Worldwide spending on security technologies is expected to grow to $66.2 billion in 2013, a 9 percent increase from 2012, according to market research firm Gartner Inc.

Palo Alto raised $299.5 million in its July 19 IPO, when it sold 7.13 million shares, including an over-allotment.