Dhaka, Mar 3: Bangladesh said Monday it expected to file a lawsuit against Hyundai for cracks found in a billion-dollar bridge built by the firm in the country's biggest construction project ever.

"We are looking into the pros and cons of the legal action. But ultimately we will sue them for the faults in the Jamuna Bridge," said communications ministry secretary Mahbubur Rahman.

Experts Bangladesh had consulted had blamed flawed construction and design for the cracks, he said.

The bridge built by the South Korean firm spans the Jamuna River 110 kilometres (68 miles) northwest of the capital Dhaka.

The South Korean ambassador to Bangladesh, Suk Bum Park, on Sunday met communications minister Ghulam Quader and urged him to reconsider the decision, according to a report by the private UNB news agency.

The ambassador said the decision appeared to have been taken "hastily." "Hyundai is a reputed company and it's not fair to blame the company for the expanding cracks in the Jamuna Bridge without any examination," the ambassador was quoted as saying.

The law ministry, however, was already working on the case and a consultant had been appointed to inspect the cracks again before the government finally went ahead, added Rahman.

The 4.8-kilometre (three-mile) long multi-purpose bridge, which was opened in 1998, provides a vital link between central and northwestern districts by crossing the mighty Jamuna, known as the Brahmaputra in India.

It is the twelfth longest bridge in the world, according to the Bangladesh government.

Thousands of cars, buses, and lorries, as well as trains, use the bridge daily. Cracks were first detected last year, prompting the authorities to impose limits on the number of vehicles allowed to cross at any given time.