Symantec's CEO John Thompson has again found himself defending his company's planned purchase of Veritas amid continued investor concerns about the company's strategy and Microsoft looming presence in the security market.

Addressing reporters during a roundtable discussion at the RSA Conference, Thompson rebutted suggestions that the Veritas merger is a defensive move driven by Microsoft's growing ambitions in the security market. "I couldn't care less about what Microsoft does," he roared.

Instead, he said, Symantec's purchase is an expansion into data protection and availability, something he believes customers want. "We are determined to get this done. Regardless of how the equity market responds, we are going ahead with it."

Thompson also dismissed suggestions that Microsoft's move to integrate its spyware tool for free into future Windows versions would hurt Symantec's own spyware products, which the company recently touted as part of its anti-virus suite.

"We are convinced that we can whip Microsoft in the market," he said, adding that Symantec would not be "whining in Washington" about Microsoft's moves.

Several large users of Symantec's products were on hand to express their support for the company's strategy.

There is a growing need for security technologies that can help companies enable better integrity and availability of stored data, said Tom Jones, director of security for California's Health and Human Services Department. As an organisation that handles more than 150,000 customers in a regulated industry, the agency faces a huge challenge in protecting the more than 300TB of data it currently stores, Jones said. "Our protection requirements are all focused around HIPAA," Jones said. Using point products to protect data won't be good enough in the long term.

Chevron Texaco has begun taking a more integrated view of the operational risks posed by its information technologies, said Richard Jackson, the company's chief information protection officer. Chevron Texaco's IT infrastructure includes more than 40,000 desktops, 8,000 laptops, 750 servers and over 500TB of data stored around the world. "We are integrating information risk components into a single-risk entity" to enable better security of this data, Jackson said. "Decision quality is central, so integrity of data is crucial," he said.

Those comments come at a time when Symantec, the industry's largest pure-play security vendor, is under growing pressure from investors to justify its planned purchase of Veritas, a slower-growing vendor of storage technologies. Since the deal was announced, the company's stock has lost more than one quarter of its value.

Adding to that pressure is Microsoft's looming presence. In the inaugural keynote at the RSA Conference, Bill Gates outlined Microsoft's intention to offer anti-virus, anti-spyware and firewall technologies.