Order for custom field after the loop

i have this table. Each post have a custom field with "region" and "city".

01 > SP > São Paulo

02 > RJ > Rio de Janeiro

03 > SP > Campinas

04 > RJ > Niteroi

This query is working perfect for show all posts in "Region = SP".

    <?php 

query_posts( array(
 'post_type' => 'hotel',
 'post_per_page' => '500',
 'meta_key' => 'hotel-region',
 'meta_value' => "sp")
  );

 ?>

01 > SP > São Paulo

03 > SP > Campinas

But now i need order the query results for city A > Z. How i can change the code for this?

Thank's