Centerplan Cos., which is leading a $400 million development in Hartford, including a minor league ballpark, is looking to the north for a new project: a casino.

The Middletown-based development company submitted the proposal for East Windsor, said First Selectman Robert Maynard. It is one of five proposals from four towns for a Hartford-area casino, which would be the third in Connecticut.

Maynard declined to identify the site, but he said it is not far off I-91 in the area of Route 5. The location, Maynard said, would not dramatically change the rural character of the town.

The state's third casino would be operated jointly by the Mohegan and Mashantucket Pequot tribes. State leaders and the tribes hope it will fend off competitive pressures posed by a gaming complex currently under construction in Springfield. Connecticut could lose tens of millions of dollars in gambling revenue to the Springfield casino, analysts say.

The tribes aim to open the Hartford-area casino a year or more before the opening of the Springfield facility, scheduled for 2018; but they still must secure final approval from state lawmakers to expand gaming in the state beyond the flagship gambling complexes in southeastern Connecticut.Founded in 2006, Centerplan is the leading partner in the massive Downtown North, or "DoNo" redevelopment project at Main and Trumbull streets in Hartford. The project seeks to transform a long vacant, desolate stretch of parking lots just north of the center of downtown. The ballpark, Dunkin' Donuts Stadium, is now under construction, the first phase of what is planned as a mixed-use development of apartments, shops and restaurants, a hotel and a grocery store.Centerplan also has been particularly active in New Haven, including a $50 million mixed-use development at the corner of College and George streets. Robert Landino, Centerplan's chief executive, is a New Haven native and a former Democratic state representative.Landino declined to comment, referring questions to the tribes. A spokesman for MMCT, a joint venture formed by the tribes for the third casino, declined to comment Wednesday or identify the East Windsor site.In the days leading up to the Nov. 6 proposal deadline, East Windsor officials had maintained they expected two proposals involving the town.One proposal was expected to come from the municipality, targeting the vacant Showcase Cinema and Walmart properties on Route 5, off Exit 44. The other was expected from a private developer for an undisclosed location — a developer that Maynard says is Centerplan.Denise Menard, the former East Windsor mayor who lost a re-election bid last month, confirmed recently that the town abandoned its proposal for the movie theater and store properties in the final hours before the deadline. The proposal would have been too complicated, Menard said, because the town did not have control of the properties.Maynard, Menard's successor, said he supports establishing a casino in East Windsor because "it would help the town a great deal economically."In addition to East Windsor, the tribes' joint venture has sent out letters to officials in East Hartford, Hartford and Windsor Locks — towns where there are competing proposals — urging them to move forward with town approvals. The letters also said that MMCT will "compensate" towns that choose to hold a referendum.East Windsor officials have long said they support holding a referendum, asking residents to vote on the idea. Maynard said he also endorses that approach.MMCT has said it anticipates choosing a location for the Hartford area casino by Dec. 15, in time to submit it for legislative approval in the next legislative session.Last week, Windsor Locks set out a schedule for a public hearing and referendum. The town has two proposals, from Bradley International Airport and from Sportech Venues, which operates a betting parlor in the same building as Bobby V's Restaurant and Sports Bar.The proposal for East Hartford targets a flashy makeover of the long-vacant Showcase Cinemas on I-84. The city of Hartford said it did not have any specific locations but submitted to the tribes to keep its options open.