HP announced today that it has signed a definitive agreement to acquire ArcSight, a security and compliance company, for $1.5 billion at $43.50 per share. There were rumors of the acquisition going around over the weekend, but the companies have now made it official. 

HP says that the acquisition will help it improve security, reduce risk, and facilitate compliance at a lower cost for its customers. "ArcSight’s superior technology is highly complementary to HP’s existing security portfolio of hardware, software and services," the company says. 

HP also says the deal will make it better positioned to deliver broader visibility, deeper context, and better continuity. 

"HP’s acquisition of ArcSight will enable the creation of a new type of security solution, one that serves the modern enterprise," said ArcSight President and CEO Tom Reilly." By combining ArcSight’s Enterprise Threat and Risk Management Platform with HP’s breadth of application development and operations management solutions, HP will be able to offer an integrated security platform that delivers broader visibility, deeper context and faster remediation of enterprise-wide security and risk-related events. In a world where perimeter security is no longer enough, businesses need this holistic approach to securing their networks, applications and sensitive data."

The deal is subject to customary closing conditions, and is expected to close by the end of the year.