An apparatus for obtaining “shrink sleeve” labels, comprises a carousel that is provided peripherally with a plurality of spindles configured for being wound from portions of plastic film, a sealing device cooperating with said spindles means for sealing opposite edges of said portions for obtaining said “shrink sleeve” labels, said sealing device comprising a laser device; a method for labelling containers, comprises in sequence: advancing a plastic film in an advancing direction; cutting said plastic film transversely to said advancing direction to obtain a portion of plastic film; winding said portion in such a way as to make opposite edges of said portion overlap one another; joining together said edges to obtain a “shrink sleeve” label, said joining comprising sealing by means of a laser beam.