By Antonio Denti

GROSSETO, Italy (Reuters) - The manslaughter trial of the captain of the Costa Concordia cruise ship, which capsized off Italy's coast last year killing 32 people, began on Tuesday and was immediately suspended because of a lawyers' strike.

The giant Concordia flipped on its side outside the Tuscan port of Giglio in January 2012 after it struck rocks during a maneuver that brought it too close to shore.

Captain Francesco Schettino, who left the ship before all its crew and passengers had been rescued, faces charges including multiple manslaughter and abandoning ship.

He argues he managed to prevent a worse disaster by steering the vessel into shallow waters after the impact to help the rescue operation.

He attended the hearing in the Tuscan town of Grosseto wearing a blue suit and sunglasses, declining to answer questions from a scrum of reporters.

Domnica Cemortan, a Moldovan woman who has said she was with Schettino at the time of the accident, watched the short hearing. Prosecutors have said they will call her as a witness.

The trial was immediately postponed until July 17 because the lawyers involved in the case were taking part in a nationwide strike protesting against measures to streamline civil trials.

The Concordia accident triggered a chaotic night-time evacuation of more than 4,000 passengers and crew from the 290-metre-long ship (951-ft), which still rests on a rock shelf outside Giglio port.

If found guilty, Schettino could face up to 20 years in jail, which his lawyer Domenico Pepe said was disproportionate, adding that events had been misconstrued.

"The captain did not abandon the ship, he fell off of it," as the cruise liner tilted, Pepe told reporters after the hearing.

State prosecutors rejected a plea bargain offer from Schettino in May but accepted those of five other officials, including four ship's officers and the crisis coordinator of the vessel's owners, Costa Cruises.

Daniele Bocciolini, a lawyer representing victims, told reporters on Tuesday he hoped investigations would show that the trial should be widened to include all those responsible.

"I think, even though Schettino is the only one on trial, he is not the only one responsible," Bocciolini told reporters.

Costa Cruises, a unit of Carnival Corp, agreed to pay a 1-million-euro ($1.29 million) fine to settle potential criminal charges in April. That means that for now Schettino is the only person facing trial.

(Reporting by Antonio Denti; Writing by Catherine Hornby; Editing by Andrew Heavens)