The city may try to negotiate a better deal with Lennar Urban before deciding whether to select the company to develop the Concord Naval Weapons Station. City staffers are recommending that the City Council on Tuesday delay its decision on a master developer and reopen negotiations with Lennar on five issues -- funds for affordable housing, Willow Pass Road improvements, use of binding arbitration, the right to develop future phases of the project and the firm's use of a limited liability corporation structure.