View the forms library. The Buyer Agency Contract (Form BAC) is the exclusive agency contract for buyers' and tenants' agents.An exclusive listing agreement may comprise one of the following: (1) The exclusive agency of the broker. The Howard Hanna Allegheny Valley real estate office services Allegheny County, Westmoreland County, Butler County and Armstrong County. Allegheny Real Estate, Kittanning, Pennsylvania. Find real estate agency Allegheny Real Estate in KITTANNING, PA on realtor. Com®, your source for top rated real estate professionals.