splitter.pl

#!/usr/bin/perl
use PerlIO::gzip;

$filename = 'YOUR_FILENAME.gz';
$limit = 1000000;

$fileno = 1;
$line = 0;

while (<>) {
    if (!$fh || $line >= $limit) { 
        open $fh, '>:lzop', "$filename_$fileno.lzo"; 
        $fileno++;
        $line = 0; 
    }
    print $fh $_; $line++;
}