I just picked these up the other day from a seller in Portugal. In the listing, he stated...
"These are Portuguese Army M/913 supporting utility straps made by M.E.Co for the Portuguese Army during World War One.
Portugal had adopted the Mills webbing early in 1913, a very similar variant of the British pattern 08 webbing, and this was the main equipment used by the Portuguese troops sent to Flanders during World War One.
Many of these sets were made in Portugal with components imported from the Mills Equipment Company (M.E.Co) but as the war progressed and in particular after the Georgette offensive by the Germans and the heavy loss of men and materiel by the Portuguese Expeditionary Force the quantity of materiel directly supplied by M.E.Co increased.
These type of straps were carried over to the M/943-44 webbing (a variant of the British Pattern 37) and used along other items until the early 60's.
These straps were made by M.E.Co in 1918 and supplied to the Portuguese Army, these are clearly marked and in very good condition for their age."
I guess this makes sense as they are not broad arrow marked and are 22 inches in length, rather than the 32 inches of the Pattern 1908 support strap.