Shares in US-based cruise ship operator Carnival slumped here on Monday, after the group admitted that the Costa Concordia disaster could cost the group $85-95 million (67-75 million euros). Carnival Corp\'s share price tumbled 16.86 percent to 1,868.99 pence in afternoon London deals on London\'s FTSE 100 index of leading companies, which was 0.24 percent higher at 5,651.11 points. The group, which is listed in London and New York, is the owner of the luxury liner which ran aground late Friday off the Italian coast with the loss of at least six lives. Carnival said in a statement that its priority was the \"safety of our passengers and crew\" and expressed condolences to the families of those who had died when the ship grounded and then pitched over to leave it half-submerged. \"A damage assessment review of the vessel is currently being undertaken to determine how long it will be out of service,\" it said in a statement. \"The vessel is expected to be out of service for the remainder of our current fiscal year if not longer. \"For the fiscal year ending November 30, the impact... for loss of use is expected to be approximately $85-$95 million. \"In addition, the company anticipates other costs to the business that are not possible to determine at this time,\" it added. Carnival Corp is the parent company of Costa Crociere (Cruises), the operator of the ship. The Costa Concordia ran aground off Giglio Island late Friday, with rescue services still working Monday to search the ship and surrounding waters. About 15 people, including Italians, Americans and French nationals, are still missing after the massive ship hit rocks and capsized shortly after it began a seven-day Mediterranean cruise. \"It seems that the commander made errors of judgement that had serious consequences,\" said a statement Sunday from Costa Crociere, referring to Captain Francesco Schettino. \"His decisions in the management of the emergency did not follow Costa Crociere\'s procedures which are in line with international standards.\"