Another option is:

use strict;
use warnings;
use Data::Dumper;
use Regexp::Common qw/balanced/;

my $string = "<*2>FOO<2,1>,<*3>(SigB<8:0:2>,BAR),<*2>Siga<2:0>,Sigb<8,
+7,6,5,0>";
print "$string\n";

my @parts = $string =~ m/(?:$RE{balanced}{-parens=>'()<>'}|[^,<(]+)+/g
+;

print Dumper(\@parts);
[download]

which produces

<*2>FOO<2,1>,<*3>(SigB<8:0:2>,BAR),<*2>Siga<2:0>,Sigb<8,7,6,5,0>
$VAR1 = [
          '<*2>FOO<2,1>',
          '<*3>(SigB<8:0:2>,BAR)',
          '<*2>Siga<2:0>',
          'Sigb<8,7,6,5,0>'
        ];
[download]