This paper deals with the characterization of two classes of monotonic
and neutral (IMV) aggregation operators. The first class corresponds
to (MN) aggregators which are stable for the same positive linear tran
sformations and present the ordered linkage property. The second class
deals with (MN)-idempotent aggregators which are stable for positive
linear transformations with same unit, independent zeroes and ordered
values. These two classes correspond to the weighted ordered averaging
operator (OWA) introduced by Yager in 1988. It is also shown that the
OWA aggregator can be expressed as a Choquet integral.