(Reuters) -Maritime labour unions in Argentina announced on Thursday they would cease all activities in ports for 48 hours.

The United Maritime Workers Union in a post on Facebook said that the Tugboat Owners Chamber (C.A.R.) has refused to negotiate an expired bargaining agreement, prompting the union to halt work.

However, in light of concerns over potential energy supply shortages, the union confirmed that tugboats, which guide vessels supplying thermoelectric power plants and LNG gas tankers, will continue operations.

The exception was made to prevent additional pressure on the energy sector.

(Reporting by Natalia Siniawski; editing by Jason Neely)