A transversely extensible elastic laminar web material 100 comprising - a first and a second web material 102, 104, each of which defines a first and a second distal region 1021, 1022, 1041, 1042 adjacent to corresponding longitudinal side edges 1023, 1024, 1043, 1044 and a central region 1025, 1045 between the aforesaid distal regions 1021, 1022, 1041, 1042, - at least one web of elastomeric material 106 applied to these central regions 1025, 1045 of the first and second web materials 102, 104, and - a plurality of connection formations 160 applied to at least one distal region 1021, 1022, 1041, 1042 of said first and second web materials 102, 104 and projecting from a respective longitudinal edge 1023, 1024, 1043, 1044. In the transversely extensible elastic laminar web material 100, the elastomeric web material 106 and the connection formations 160 are interposed between said first and second web materials 102, 104 and are joined thereto by mechanical welds 355 and 365.
