Swedish defence firm Saab AB has agreed to buy the Swedish marine defense unit of ThyssenKrupp AG for 340 million kronor ($50 million), expanding the maker of Gripen jet fighters’ business to manufacturing submarines and stealth corvettes.

“An important task is to achieve synergies with Saab’s existing marine activities,” the Stockholm-based company said in a statement yesterday. “This work must take its course while starting delivery of development, maintenance and products to the Swedish market.”