A deal would give Norwegian Cruise, a company with a market value of $6.8 billion, access to Prestige Cruises’ luxury cruise ships and affluent clientele as it competes with bigger rivals Royal Caribbean Cruises Ltd (RCL.N) and Carnival Corp (CCL.N). The owner of Prestige Cruises, private equity firm Apollo Global Management LLC (APO.N), also owns a 20 percent stake in Norwegian Cruise.