Updated

The Italian owners of the Costa Concordia ship that capsized off the Tuscan coast are considering six proposals to remove the vessel -- a massive, yearlong operation that may involve breaking up the massive liner.

Costa Crociere SpA said in a statement Friday that each plan submitted for bidding consideration envisages a 10-12 month salvage operation. And each one focuses on ensuring the least environmental impact around the tiny island of Giglio, which is in a marine sanctuary, Costa said.

The Concordia slammed into a reef off Giglio Jan. 13 after the captain veered off course and steered the liner close to port in an apparent stunt. Twenty-five people were killed and seven others are missing and presumed dead following a hectic and delayed evacuation.

Costa, a unit of Miami-based cruise giant Carnival Corp., released few details of the six competing bids, saying only that some of the plans may involve removing some external parts of the ship. That would allow for the hull to be more easily dislodged from the rocks where it is currently perched, Costa said.

Experts have expressed doubt that such a huge liner can be simply refloated and removed intact.

But cutting up the ship raises serious environmental concerns for the pristine waters around Giglio, which is heavily dependent on tourism.

The winning bid is expected to be announced later this month or next.

Removal of the ship cannot begin until all 500,000 gallons of fuel have been extracted from the ship's tanks. That pumping operation, which has been under way for several weeks, was hampered Friday by poor weather, civil protection officials said.

The Concordia's captain, Francesco Schettino, is under house arrest and accused of manslaughter, causing a shipwreck and abandoning the ship before all 4,200 passengers and crew were evacuated. He has denied the charges and insisted the reefs, which are on most tourist maps, weren't on his nautical charts.