regex to match a string that could extend over several lines

regex to match a string that could extend over several lines

I have examples in a text document line this:
set ( blah blah blah )
and
set ( blahlblah
blahlbal )
and
set ( blah
blah
blah
blah
blah )
I am using text mate and want to find these and replace with nothing
I got this to work with one line but stumped on how to do this over
multiple lines. I tried this:
SET \(.*\n.*\)