Palo Alto Networks, other tech firms tee up IPOs

NEW YORK – A series of technology companies, including security software maker Palo Alto Networks, are preparing to go public on the heels of Facebook’s $5-billion filing, sensing a window of opportunity as the stock market rallies.

Technology management software maker ServiceNow, human resources software provider Workday, machine data software company Splunk and flash memory maker Violin Memory are also in various stages of planning public offerings this year, sources familiar with the matter said.

These companies are expected to be valued at $1 billion and higher, they said.

Palo Alto Networks, the largest of these firms, is expected to start the process of picking bankers as soon as this week to underwrite its IPO, while ServiceNow has picked Morgan Stanley and Goldman Sachs to lead its offering, the sources said. Both the companies are aiming for an offering in the first half of this year, the sources said.

Workday has drawn up a shortlist of underwriters, the sources said, but the names of the banks couldn’t be learned. Violin is in early talks with banks about a possible filing this year, the sources said.

Splunk filed its registration statement with the U.S. Securities and Exchange Commission, with Morgan Stanley, Credit Suisse, JPMorgan Chase & Co. and Bank of America Merrill Lynch leading the offering.

Palo Alto Networks and Workday declined to comment. ServiceNow, Splunk, Violin, Goldman and Morgan Stanley were not immediately available for comment.

The IPO plans come after Facebook, LinkedIn Corp. and Groupon Inc. have gone public or are planning IPOs despite a broader freeze in the markets in the last few months amid the European debt crisis and global economic uncertainty.

Having said that, the S&P 500 .SPX is up more than 8 percent so far this year.

For most of these companies, the IPO route is most likely since they have become too expensive to buy out.