Manila - The Philippines would no longer resume diving operations to retrieve hundreds of bodies trapped in a ferry that sank during a typhoon and would instead re-float the vessel, a transportation official said Wednesday.

Transportation Undersecretary Elena Bautista said Sulpicio Lines, the owner of the capsized MV Princess of the Stars, was now scouting for a salvage company that specializes in re-floating ships to do the job.

"We have made a decision that we will just re-float the ship because this is the safest option," she said.

Bautista, however, admitted that re-floating the ferry would prolong the agony of family members waiting to recover the bodies of their relatives that have been presumed dead and trapped inside the ferry.

More than 550 people are still missing and presumed dead from the sinking, the country's worst maritime disaster in two decades. Their bodies are believed to be trapped inside the capsized vessel.

"Re-floating is not a fast process, it might take about two to three months to re-float the vessel," Bautista said. "I hope the people will understand this. But it is the best way to get all the bodies out."

Last week, the government halted diving operations at the submerged wreckage to protect divers from possible contamination from a cargo of highly toxic pesticide that the ferry was carrying when it sank.

Doctors warned that the pesticide, endosulfan, attacks the nervous central system and could kill humans.

While the waters in the area have tested negative for any contamination, Bautista said experts warned that there were too many risks in a previous plan to bore a hole on the side of the sunken ferry to get the hazardous cargo.

"Even if we cut through the vessel, we are not sure if we will be able to get the cargo," she said.

The Princess of the Stars capsized off Sibuyan Island, 300 kilometres south of Manila, on June 21 when it sailed straight into the path of Typhoon Fengshen.

Only 56 survivors have been found after the accident, while 250 are confirmed killed after their bodies were recovered in nearby waters or shores.

Bautista said Sulpicio Lines has been told to choose before the weekend the salvage company that would re-float the Princess of the Stars.

"We will make sure that they will have a decision before the weekend because we are running against time," she added.

The Princess of the Stars was the fourth ship of Sulpicio Lines to be involved in a major accident since 1987, when the company's MV Dona Paz collided with an oil tanker just before Christmas, killing 4,341 people in the world's worst peacetime shipping disaster.

Aside from the ferry sinking, Typhoon Fengshen caused landslides, massive floodings and other accidents that killed 540 people in the Philippines, with 41 still missing. Authorities estimated the cost of Fengshen's damages at nearly 10 billion dollars. (dpa)