Legally binding document setting the terms of a bond sale between a bond issuer and an underwriter. The information stated on an agreement include sale price, sale conditions, interest rate, maturity, redemption provisions, sinking fund provisions, and conditions that may cancel the contract. Usually done on new bonds, the issuer delivers these bonds to the underwriter and the latter pays the issuer for them. Then, the underwriter put these bonds on the market at the indicated price and yield while the investors acquire the instrument from the underwriter. The underwriter, upon collecting the proceeds, generates profit based on the spread or difference between the buying price and the selling price.