The system is the Saab 2000 Airborne Early Warning and Control aircraft and is currently operated in Asia by Thailand and Pakistan.
Saab didn't disclose the identity of the latest customer.
"The industry's nature is such that depending on circumstances concerning the product and customer, information regarding the customer will not be announced," it said.
Saab's 2000 AEW&C aircraft is equipped with the advanced Erieye radar system, which is based on active electronically scanned array technology, providing wide-area surveillance.
"Our surveillance system provides the customer with improved solutions for defense and civil security," said Gunilla Fransson, head of Saab's Security and Defense Solutions business area. "This contract is a result of our close cooperation with our customer and can be seen as a further confirmation of our strong capability to provide our customers with advanced service and support solutions."
The contract runs until 2017, the company said.