The deal gives McAfee, a unit of chipmaker Intel, an expanded portfolio of next-generation firewalls and other products for network security, a joint statement said.
"With the pending addition of Stonesoft's products and services, McAfee is making a significant investment in next-generation firewall technology," said McAfee president Michael DeCesare.
"Stonesoft is a leading innovator in this important market segment. We plan to integrate Stonesoft's offerings with other McAfee products to realize the power of McAfee's Security Connected strategy."
Based in Helsinki, Finland, Stonesoft has some 6,500 customers across the globe.