Opera suffered a “technical issue” upon arriving into the city on Sunday (2 June), causing it to hit the moored River Countess.
MSC said despite repair works to Opera being completed, it was still awaiting the conclusion of an investigation into the incident by authorities, which was "taking a few days longer than originally expected".
As a result, the ship’s next cruise, with embarkations scheduled from Bari on 8 June and Venice on 9 June, had been cancelled.
"We have informed our guests and business partners about the cancellation, and are offering a number of alternative options, including a full refund of their cruise fare and incurred travel expenses, as well as any pre-booked services," MSC said in a statement.
The line is also offering a 50% discount on a future seven-to 21-night cruise before the end of 2020 to affected passengers.