EAST HARTFORD — Construction of a new outlet mall at Rentschler Field is expected to start in mid-September. “The town continues to facilitate, as much as possible, the development commencement and completion,” Mayor Marcia Leclerc said Thursday.A town agreement with the developer, Michigan-based Horizon Group Properties, “is in the process of being finalized,” she said, while adding that she will “consider bringing the issue of tax abatement to the Town Council” after plans are more complete.Horizon officials have not replied to requests for comment.Leclerc acknowledged that leasing is moving ahead gradually for the retail facility, adding that “the pace is reflective of today’s cautious retail market.”Still, Horizon recently has secured “several more tenants, and expects additional leases to be signed this month,” Leclerc said. “As reported to the town, outlet shopping is a sector of retail which remains strong,” she added.Leclerc added that discussions between the United Technologies Corp., which owns the land, and the developer have continued over the signing of a ground lease.“It is our understanding they are projecting a mid-September start date with a completion and opening in the spring of 2019,” she added.The project had been lagging, and developers missed previous deadlines, even for a time appearing to stall the outlet mall plan. A July deadline was extended, Town Council Chairman Richard Kehoe said a month ago.The council in June canceled a planned meeting to discuss property tax abatements for Horizon, after UTC indicated the developer had missed the corporation’s deadlines for discussing the land lease on the property, which is adjacent to UTC’s Pratt & Whitney plant and headquarters.The shopping center plan includes about 100 stores, a food court, and an outdoor playground. Developers have said they intend to create a “campus” environment that would appeal to workers at the neighboring Pratt facilities.Some site work actually began in 2015, and the shops originally were projected to open this May. After little initial progress, however, the development’s completion date was pushed back to spring 2018, which since has been delayed until 2019.Leclerc also previously said that the project has met the requirements for state funding through the quasi-public investment agency Connecticut Innovations.The Rentschler property already hosts a Cabela’s Outdoor Outfitters, which opened in 2007, and the 40,000-seat Pratt & Whitney Stadium at Rentschler Field, which opened in 2003. It hosts University of Connecticut football games and a variety of entertainment events.