The stricken ship Costa Concordia will be removed from the Italian coast between June and September - later than originally planned, officials have said.
The vessel has been resting on its side off the Tuscan coast since it capsized last year, killing 32 people.
Speaking on the eve of the first anniversary of the disaster, officials highlighted the difficulties of the salvage operation, including the huge size of the vessel and environmental concerns.
Franco Gabrielli, the chief of Italy's Social Defence Department, said officials were looking to remove the ship between June and September, depending on weather conditions.
Originally, they had hoped to have it removed in the spring.
The Concordia slammed into a reef off the island of Giglio on January 13, 2012 after its captain took it off course in a stunt to bring the ship closer to the island. As it took water in, the ship rolled onto its side.
The salvage efforts will also require 400m euro (£331m) - up from the 300m euro originally estimated.
Sky's Europe Correspondent Robert Nisbet says the delays and overspending are linked to the technical complexities of an unprecedented operation involving a ship the length of 11 football fields and weighing twice as much as the Titanic.
Officials want to remove it as opposed to breaking it up on the site because the waters surrounding Giglio are of particular environmental significance - part of a marine sanctuary and a favourite spot for scuba divers.
The ship's captain, Francesco Schettino, has been accused of multiple manslaughter, causing a shipwreck and leaving the ship before all passengers were evacuated.
Since the tragedy, the Costa Concordia has turned into a macabre tourist attraction, with hundreds of sightseers catching a ferry from Porto Santo Stefano to Giglio so they can look at the ship and take pictures before returning to the mainland.
Sunday's anniversary commemorations in Giglio include a ceremony to honour rescue teams and a mass held in the island's tiny church, where many of the injured were treated.
A memorial in honour of the 32 dead will also be unveiled.
But the commemorations have been marred by controversy over a letter reportedly sent by ship owner Costa Crociere to survivors, telling them not to bother attending the ceremonies.
The company cited logistical difficulties on the tiny island and the desire for privacy expressed by the families of the victims, according to news reports.
Some 4,200 people between passengers and crews survived the tragedy.