Negotiations to end a row that has stopped work on the Panama Canal expansion have hit "serious disagreements," the canal administrator has said. Work has been suspended for two weeks, as the main contractor, the GUPC consortium led by Spanish group Sacyr, and the canal administrator fight over who should pay $1.6 billion in cost overruns. "While last week the parties seemed to have reconciled their positions on different points of the discussions, at the point of putting these rapprochements down on paper, serious disagreements appeared," the Panama Canal Authority said Tuesday evening. GUPC wants Panama to add the sum to the initial contract fee of $3.2 billion, saying unforeseen geological difficulties forced them to spend much more on cement than expected. They say that they based their estimates on data provided by the Canal Authority that were incorrect. The canal authority wants to get construction back underway with both sides contributing $100 million as negotiations on a final agreement continue. The canal expansion is one of the world's most ambitious civil engineering projects and aims to widen the canal to accommodate massive cargo ships. The project was due to be completed next year. The original canal, built by the United States mostly with workers brought in from the Caribbean, was opened in 1914, and now handles five percent of global seaborne trade