Come to an agreement to lower pay (6)
I believe the answer is:
settle
This clue is a triple definition!
'come to an agreement' is the first definition.
(I've seen this in another clue)
'to lower' is the second definition.
(thesaurus)
'pay' is the third definition.
(as in settling a bill)
(Other definitions for settle that I've seen before include "reach a decision" , "Become established and pay debt" , "place to sit" , "Become established or pay bill" , "near Giggleswick" .)