YOu can independently discover someone to buy your sector or selling with a assistance like Sedo, BuyDomains or Upgraded.com where you can basically publish your sector on the market but not actually have it 'brokered' or 'auctioned' .
I only give advice, for those of you who like to play and post the link, I have a web test and get a PR from the list especially without intermediaries, please check www.govertise.com hopefully help.