BT Group has bought privately-held network security firm Counterpane for an undisclosed sum, though reports put it at $40 million or less.

According to Vnunet:

Counterpane specialises in providing outsourced security services for monitoring networked applications, databases and hardware for attempted breaches.

The company operates three data centres in the US and Europe. It says it currently monitors 550 networks for Fortune 100 companies and recently said it had expanded its service to cover Microsoft and Oracle databases, SAP ERP applications and IBM mainframes.

Counterpane was backed by Accel, Bessemer, Comcast, and Morgan Stanley Dean Witter Private Equity.