Form agreement for the purchase and sale of a division or line of business of a private US corporation, drafted in favor of the seller. An asset purchase agreement (APA) is a written legal document that formalizes purchasing a business or substantial commercial asset.This Practical Law Company Microsoft Word template is for a standard bill of sale to accompany an asset purchase agreement. It includes drafting notes. Purchased Assets. 1. 1.2. Both the seller and purchaser of a group of assets that makes up a trade or business must use Form 8594 to report such a sale. An asset purchase agreement is the legal document that will govern the transfer of ownership of a business's assets from the seller to the buyer.