Royal Caribbean Cruise Line has announced the signing of contracts to build two sister ships to the Sovereignof the Seas. The ships will be built at Alstrom Chantiers de l’Atlantique. Construction costs for both ships will total nearly $600 million.

“This puts an end to the speculation that our owners’ recent purchase of Royal Caribbean’s holding company, Royal Admiral Cruises, has inhibited our ability to invest in new vessels,” said Richard D. Fain, Chairman of the Board.

The contracts call for a March 1991 delivery of the first vessel, with a second ship nine months later.