"The Inner Harbor is a family attraction, and I think that's incompatible with slots," the mayor said, pledging to push the House of Delegates to delete the provision.
"I also worry about the impact on the restaurants and the businesses that thrive because of the tourist trade that comes to the Inner Harbor - Federal Hill, Little Italy and other places."
O'Malley repeated his position that any slot machines should be restricted to the Pimlico racetrack in Northwest Baltimore.
The legislation, which now goes to the House, would permit a total of 15,500 slot machines at six places around the state, three at racetracks and three elsewhere.
One of the tracks probably would be Pimlico. A second city site would have to be at least four miles away, and legislators in Annapolis have said that points to a harbor location.
Among the sites long rumored as a possible waterfront setting for gambling is the 32-story Baltimore Marriott Waterfront Hotel.
The hotel was developed by H&S; Properties Development Corp., controlled by bakery magnate John Paterakis Sr. An executive at H&S;, Michael S. Beatty, did not return a phone call yesterday.
O'Malley said he would lobby for changes to the bill as it moves through the House. "That's the real narrows in the legislative pass and where any substantive changes and amendments will happen," he said.
James Piper Bond, president and chief executive officer of the Living Classrooms Foundation, said he shares O'Malley's concerns about slots. The foundation's youth education and training center is east of the Marriott.
"The Inner Harbor has done so well without slots," Bond said. "I don't think it's necessary to improve the Inner Harbor."