An anti-slots ballot committee will modify its first radio advertisement and issue a formal retraction today after mistakenly listing a Baltimore faith-based nonprofit organization as an endorser, officials said yesterday. "We've never taken a position for or against slots," said Rob English, lead organizer for Baltimoreans United in Leadership Development (BUILD). "How dare they assume what an individual organization's position is?" Scott Arceneaux, a senior adviser to Marylanders United to Stop Slots, said that the anti-slots group mistakenly assumed BUILD was a supporter because Bishop Douglas I. Miles, a pastor affiliated with the group, had appeared at one of their anti-slots events. "I've apologized to Bishop Miles and we will change the ads and we'll put out a retraction," Arceneaux said. The radio spot started airing in the Baltimore market yesterday. Arceneaux said the anti-gambling group has bought $50,000 worth of airtime this week and hopes to continue airing ads until November, with television commercials closer to Election Day.