Rialto Theaters, operator of Berkeley's popular Elmwood Theater as well as Santa Rosa's Lakeside, may assume operatorship of the recently vacated Cerrito Theater. Rialto was chosen from among seven firms who submitted proposals to El Cerrito's Redevelopment Agency and City Council over the last two weeks. In a decision reached at last night's City Council meeting, Rialto Theaters was officially recommended as the successor to Parkway Theaters, who operated the theater before going out of business late last month. The next step: Rialto and the city will attempt to hammer out a lease by June 29 -- the deadline that the city has given itself to approve a new lease agreement. If all goes as planned, Rialto Theaters could be stepping in as new operator of the Cerrito Theater by early July.