Michael Thamm, CEO of Carnival Corporation’s Costa Group, is leaving the company immediately, according to a report in German media, as well as a letter sent internally at Carnival Corp. and obtained by Cruise Industry News.

The Costa Group, which oversees Carnival’s AIDA and Costa brands as well as other operations, will now see the brand presidents of Costa and AIDA report directly to Carnival Corp. CEO Josh Weinstein, according to the report.

Carnival Corp.’s letter said Thamm’s position will not be filled.