$_ = "<*2>FOO<2,1>,<*3>(SigB<8:0:2>,BAR),<*2>Siga<2:0>,Sigb<8,7,6,5,0>";
@line = split(/ ,         # comma...
                (?!       # not followed by
                   [\w,]+ #    "word" characters or commas and
                   [>)]   #    a close-bracket or close-paren
                )
              /x, $_);
print join($/, @line), $/;