Voters will consider authorizing the town to convey a parcel of land to a developer proposing an assisted living facility on Main Street at a Special Town Meeting on Thursday at 7 p.m. in Galvin Middle School. The 18,000-square-foot parcel at 344 Main St. is part of a parking lot now used by the town and two banks that also own portions of the lot. Brightview seeks to build an assisted living facility on the adjacent site of the former Fraen Corp. complex, according to town administrator Stephen P. Maio. The town meeting article would allow the town to convey its share of the lot to Brightview at no charge as part of an arrangement in which the developer would also build a 198-car parking garage on the site for use by its future residents, the town, and the two banks, Maio said. Both banks are negotiating the sale of their portions of the lot to Brightview. A separate article would allow the town to enter into a 99-year lease for use of 123 spaces in the garage, another component of the plan. The lease would require the town to provide Brightview with $105,000 annually for 20 years n the form of tax relief, but no money after that. The meeting will also take up three articles providing minor revisions to a zoning change approved by town meeting in 2012 that created an assisted living district in that area of Main Street. The revisions are needed for the proposed project.