The damaged Vale Beijing, the world's largest iron-ore carrier, was moved from its berth in Brazil for repairs on Tuesday, opening up space at a port responsible for about 10 percent of the world's iron ore exports, the Harbour pilot's office said.

Tugs moved the massive ship from the dock at about 10 a.m. (1300 GMT) in the port in Sao Luis in northeastern Brazil and will tow it to a location outside the shipping channel, a Harbour pilot official told Reuters.

The official added the ship - owned and operated by South Korea's STX Pan Ocean <028670.KS> - could not use its own engines for fear that they may further damage the Vale Beijing, which is longer and wider than three soccer or U.S. football fields end to end.

The port in northeastern Brazil, known as Ponta da Madeira, is operated by Vale , the world's second-largest mining company, which has a long-term contract with STX to ship iron ore.

The 384,300 tonnes of ore loaded aboard the Vale Beijing, enough to make steel for nearly 3-1/2 Golden Gate Bridges, was mined by Vale at its giant Carajas complex in Brazil's Amazon region.

A crack in the ship's ballast tanks was either the result of loading its holds or because of a structural problem, said the official, who asked not to be identified. Vale said on Tuesday it had no new information on the ship.

As there are no facilities to unload iron-ore at Ponta da Madeira and no large shipyards in the area, repairs will have to be made by divers while the ship is at anchor, the Harbour pilots' office said.

Harbour pilots have detailed knowledge of the harbors where they live and work and are required by law and marine tradition to go aboard all large vessels arriving or leaving a port to steer them through approved channels and clear of marine obstacles and other ships.

Their work is closely regulated by world navies and coast guards and their dispatch offices track marine traffic and activity for the entire ports and harbors.

(Reporting and writing by Jeb Blount; Editing by Stuart Grudgings and Sofina Mirza-Reid)