Dec 14 (Reuters) - CNH Industrial"s (CNHI.MI) unit Iveco and Air Liquide (AIRP.PA) have signed a memorandum of understanding to speed up the development of hydrogen heavy-duty mobility in Europe, the Italo-American parent and the French industrial gas company said on Tuesday. The partnership is aimed at studying "the roll-out of heavy-duty fuel-cell electric long-haul trucks coupled with the deployment of a network of renewable or low-carbon hydrogen refuelling stations" along major trans-European transport corridors, the two companies said in a joint statement. Vehicle maker CNH Industrial has said it plans to complete the spin off its truck and bus units and its FPT engine division at the beginning of next year and list them under the Iveco Group name. read more