LEWISTON — The City Council signed off on a purchase-and-sale agreement Tuesday for the redevelopment of the former Martel School on Lisbon Street.

The agreement gives developer Avesta Housing the option to purchase the property, contingent on receiving low-income housing and historic preservation tax credits toward a planned 44-unit senior housing complex.

Avesta, which is partnering with the Lewiston Housing Authority, has redeveloped a number of former school buildings into senior housing projects.