#!/usr/bin/perl

use strict;
use warnings;

my @unsorted;
my @sorted;

while (<DATA>) {
    push @unsorted, [split /\s+/, $_];
}

@sorted = sort { $a->[3] <=> $b->[3] } @unsorted;
print join " ", @$_, "\n" for @sorted;

_ _DATA_ _
Firma1 8263112 94626384523 16
Firma2 8263112 94626384523 33
Firma3 8263112 94626384523 04