The Financial Post reports in its Wednesday edition that Ukraine is pushing for grain exports to continue from key ports following Russia's withdrawal from the Black Sea grain deal. A Bloomberg dispatch to the Post reports that insurers and shippers are not so sure. Russia's termination of the pact means it will no longer guarantee safe passage. Ukraine is calling on other nations to help facilitate shipments from three of its deep-sea ports, which were covered by the agreement. The U.S. said shipping escorts are not an option, and insurance broker Marsh on July 18 suspended its program for grain exports from Ukraine, underscoring the challenges ahead. "No sane owners will call there uninsured," said Vasilis Mouyis, joint director of Greece-based Doric Shipbrokers, which had previously had sent vessels through the shipping passage. Without the protection of the safe corridor "the Ukraine trade is dead." Ukraine's Black Sea ports are a vital artery for its grain sales abroad -- historically accounting for the bulk of shipments -- and the harvest season is now on. The deal helped clear the backlog sparked by the start of the war, but the corridor's closure could slow the next crop getting to market.