The Harland and Wolff shipyard in Belfast is up for sale.
Its Norwegian parent company, Fred Olsen Energy, is carrying out a restructure of its business and could decide to offload Harland and Wolff.
The day-to-day running of the yard, which employs 115 people, is unaffected.
It built its last ship in 2003 and now concentrates on marine engineering activities.
No price tag has been placed on the business.
The sale was reported in Friday's Belfast Telegraph.
Harland and Wolff Heavy Industries Ltd has confirmed that "as part of wider restructuring activities it is engaged in a marketing process that may lead to a potential sale of the business".