ABC’s 10 owned and operated TV stations, including KGO ABC7, have reached an agreement to have a unit of Cox Communications sell ads on their Web sites. Cox is the owner of KTVU Channel 2, and its Cox Cross Media already sells ads for KTVU’s Web site.

Cox Cross Media, or CXM, is one of several firms attempting to create a national advertising presence for local Web sites. CXM was launched in October 2007 to sell online advertising for the Web sites of 300 TV stations repped by Cox’s sales firms, and it has grown to rep more than 700 local media Web sites, including those for print and radio outlets, according to MediaWeek Online.