The identity of the customer and the number of units to be delivered weren't disclosed.
"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.
Arthur is a C-band, medium-range system that detects and locates the origin point of enemy artillery fire. It is used by a number of military forces. Among those in Europe using the system are Sweden, Norway, Denmark, Britain, Greece, the Czech Republic, Spain and Italy.
Saab said deliveries of the system to the unidentified customer will be made next year.
"Saab is a leading provider of weapon locating systems and this order is proof of our customers' confidence in the performance of the Arthur system," said Micael Johansson, head of Saab's Electronic Defense Systems business area. "We have now sold 80 Arthur systems and their availability is well proven from thousands of hours' operation."