Websense offers to buy rival SurfControl

San Diego-based Websense said on Thursday it had offered to buy U.K.-based rival SurfControl in a deal valued at about $400 million in cash. Both companies sell products designed to protect organizations from Internet threats, such as Web sites that attempt to install malicious software.

The acquisition is expected to close about four months after it wins regulatory approval. Websense is paying for the acquisition with existing cash and financing. The company expects to have a debt of approximately $180 million to $200 million after the close of the deal, it said.