Online Reputation Management is not just about SEO

Work out if SEO will help knock off the negative comments from the search results. To do this you need to analyse the sites that are coming up in the first page of search results. If they are well establish websites that have a good Page Rank and have been online for a number of years then you may need to focus your efforts else where (as listed below). This also includes “long tail” keywords as well. You could try and counter their posts by having your content appear on their competitors website but keep in mind the cost and the potential to aggravate the situation.
Research the author of the article/post and see if she/he is of a character that is receptive to discussion or someone who will post your private conversation with them online without permission. If they are receptive then address their concerns and try to fix the problem ASAP. Always treat the person with upmost respect and never snub them or start being condescending.