Actors call for throwing out lines (7)
I believe the answer is:
casting
This clue is a double definition.
'actors call' is the first definition.
(as in a casting call)
'throwing out lines' is the second definition.
(casting out lines to catch fish)
'for' is the link.
(Other definitions for casting that I've seen before include "Selecting players" , "shell across back of fort" , "Choosing actors" , "Shaping metal in mould" , "-- Vote; -- couch" .)