You (or the purchaser or transferee) must complete Form CBS-1, Notice of Sale, Purchase, or Transfer of Business Assets. An asset purchase agreement is a written legal instrument that formalizes the purchase of a business or significant business asset.Our law firm concentrates on business transactions involving Asset Purchase Agreements and commercial real estate. Find asset purchase agreement lawyers for Chicago, IL to hire. No cost to post a project to get multiple bids in hours to compare before hiring.