After years of planning and debate, the City of Rockville appears ready to redevelop its ailing business district.

The city council this week authorized the city manager to negotiate with architect Arthur Cotton Moore on a plan for remodeling Courthouse Square, the area surrounding the new county office building complex now under construction.

The city's chief planner, James M. Davis, called the Courthouse Square remodeling "the key element of the town center plan," which was devised by Moore and adopted by the council last March.

Moore's overall plan calls for the development of 420 acres of private and public land in the city's downtown with emphasis on increased housing, office space and recreational amenities.

The Courthouse Square portion of the plan will take about eight months to design, a city official said. It is hoped construction will get under way as soon as possible to coincide with the opening of the county courthouse complex now slated for September 1981.

The project will cost the city an estimated $2,095,000, which includes a $415,000 county contribution, according to a city memo. Moore's fee could be as much as 10 percent of that figure, Davis said.

The plan calls for construction of new entrance ways into Jefferson and North Washington streets and extensive landscaping projects. Included will be a street, accessible by car, running through the square area to provide a drop-off point for both shoppers and county employes.

"It will open the area to traffice at a controlled state," Davis said. "We're trying to create a plaza with a European flavor."

Future plans devised by Moore for Courthouse Square call for construction of a hotel, conference center and a farmer's market, and renovation of the historic redbrick courthouse which will be turned into a dinner theater.

Davis called the Courthouse Square project the "most visible reflection of the city's commitment to see the town center plan through to conclusion." He said a number of private developers are waiting to see construction work begin before commiting themselves to development within the town center area.