An agreement between buyers to fix (directly or indirectly) the price that they are prepared to pay, or to purchase only through agreed arrangements, limits competition between them. An example of the type of agreement, which might be made between purchasers, is an agreement as to those with whom they will deal. Such an arrangement may be caught by Section 17 of the Act if it has or is likely to have the effect of substantially lessening competition.
The same issues potentially arise in agreements between sellers, in particular, where sellers agree to boycott certain customers. This type of agreement may have and lead to a substantial lessening of competition.