STOCKHOLM — Sweden will order four FDI frigates from the French manufacturer Naval Group, backing away from the joint British-Swedish Babcock and Saab bid as well as the proposal from Spain’s Navantia.

The purchase will be Sweden’s largest defense acquisition since the early 1980s and constitutes a major step forward in building its naval capabilities.

Aboard the Visby-class corvette, HMS Härnösand, moored here near the Royal Palace, the Swedish prime minister and defense chiefs announced their intention today to negotiate for the construction of four new Luleå-class frigates, much larger than the current five corvettes the Swedish Navy currently has in service.

“The ships that best meet the Swedish requirements are therefore the French alternative. … This is the decision that the government has now taken this morning,” Prime Minister Ulf Kristersson said.

The political decision follows recommendations submitted by the Swedish Navy and the Defense Materiel Administration (FMV), which identified the preferred international partner to deliver the Navy’s most significant surface combatant programme in nearly half a century.