Author Roles to manage comments

I have a multiple author blog and since the last few days I find myself managing a lot of comments – editing or deleting them, because of they being spam or some vicious commenter… I would like some of the authors on the blog to be able to go in and edit/delete comments (on any authors’ posts). What role should I have to give them to be able to do this? I would like to avoid giving them the admin role if that can be avoided…