SOUTHFIELD ? Computer Associates has agreed to buy network management software maker Concord Communications for $330 million in cash plus the assumption of $20 million in the company?s debt.

Concord, based in Marlboro, Mass., makes software products used by businesses, such as Northwest Airlines and Bank of America, to manage the performance and availability of computer networks. The nearly 20 year old company has about 640 employees. In 2004, it had a loss of $534,000 on revenue of $106.2 million.

CA expects the acquisition to be earnings neutral in fiscal 2006 before adding to its bottom line in 2007. Chief Operating Officer Jeff Clarke confirmed CA is paying a hefty premium for Concord, the deal opens up the $3 billion market for network systems management.

The acquisition is expected to be completed within three to four months, pending regulatory approval and the approval of Concord’s shareholders.

Concord?s operations will be integrated into CA?s newly created Enterprise Systems Management Business Unit, headed by Senior Vice President and General Manager Alan Nugent.

CA operates its Midwest regional office in Southfield.