Norwegian defense officials have narrowed down their search to French and German maritime defense firms to replace Norway’s Ula-class attack submarine fleet.

French firm Direction des Constructions Navels Services, or DCNS, and German company ThyssenKrupp Marine Systems “are the strongest candidates if Norway decides to procure new submarines,” Norway’s Ministry of Defense said in a statement.

Navy officials in Oslo have “decided to focus our future efforts towards these two companies and their respective national authorities,” the statement reads.

Both companies represent the largest submarine manufacturers in western Europe. The French firm is expected to offer its Scorpene-class attack sub for the Norwegian competition. The boat is currently fielded by the Chilean, Indian, Malaysian and Brazilian navies. Officials from the German company have yet to announce which sub class they plan to offer.

“We have yet to make a decision to go ahead with a procurement program, nor have we made a decision regarding a final supplier,” Norwegian Defense Minster Ine Marie Eriksen Søreide said.

“Significant work remains before a procurement program can be presented to the Norwegian Parliament,” she added.

The winner of the deal will produce the replacement for Norway’s current Ula-class submarine fleet. The first Ula-class sub entered the Norwegian fleet in 1989 and the last was christened in 1992.

Oslo expects to keep the Ula-class boats in the fleet until 2020, which is when the replacement program is expected to begin. The tentative replacement program is expected to take over 10 years, with initial deliveries to begin seven years after a winner is selected.