A private equity firm, which invests primarily in software and technology companies, has acquired San Diego-based security firm Websense.

Austin-based Vista Equity Partners purchased Websense for about $1 billion, paying Websense shareholders $24.75 a share as part of the agreement.

With the acquisition, which was announced May 20, Websense expects to remain headquartered in its San Diego offices, according to a release from the company.

The firm specializes in mitigating corporate data theft.

Websense management anticipates that the deal will close prior to the third quarter of this year.