MILAN, July 3 (Reuters) - Italian gas grid operator Snam , steel pipe maker Tenaris and green technology firm Tenova are trialling the use of hydrogen fuel at a Tenaris steel plant in northern Italy in a bid to cut emissions, they said on Wednesday.

According to a joint statement from the groups, the trial to use hydrogen fuel in a reheating furnace at the plant in Dalmine, near Bergamo, will last six months.

It will track the performance and reliability of using hydrogen in the steel industry, the statement said, and is part of Snam's broader move to help industrial companies decarbonise.

Hydrogen's main by-product as a fuel is water vapour, along with small amounts of nitrogen oxides, making it far less polluting than fossil fuels - assuming it does not cause further pollution via leaks.

Earlier in May, Italy, Germany and Austria signed a cooperation deal to develop a hydrogen transportation network from the southern Mediterranean to northern Europe. (Reporting by Romolo Tosiani; Editing by Jan Harvey)