use strict;

for $find = "END OF EXPANDED DATA";

	open (NEW, ">", "FILE_OUTPUT.txt" ) or die "could not open:$!";
	open (FILE, "<", "FILE.txt") or die "could not open:$!";

	while (<FILE>) {
		if (/$find/){
		print NEW "\n";
	}
}
close (FILE);
close (NEW);

##</code><code>##

LINE 1
LINE 2
LINE 3
END OF EXPANDED DATA
LINE 4
LINE 5
LINE 6
LINE 7
END OF EXPANDED DATA
LINE 8
LINE 9

##</code><code>##

LINE 1
LINE 2
LINE 3
END OF EXPANDED DATA

LINE 4
LINE 5
LINE 6
LINE 7
END OF EXPANDED DATA

LINE 8
LINE 9