@companies = ("FOO,BAR");

##</code><code>##

@companies = ("FOO", "BAR");
# or
@companies = qw(FOO BAR);

##</code><code>##

# Use quotemeta if companies are not really
# foo and bar and contain metacharacters.
my $companies = join("|", map(quotemeta, qw(FOO BAR)));
print "$1\n" if $content =~ /($companies)/;