tie-in salesa type of ANTI-COMPETITIVE PRACTICE/RESTRICTIVE TRADE PRACTICE whereby a supplier requires that the purchaser of product A (the tying good) must also buy his requirements of one or more other products (the tied goods) from the seller of A. Like an EXCLUSIVE DEALING arrangement, this may restrict the freedom of the buyer to obtain these goods from rival suppliers and hence limit effective competition. Under the COMPETITION ACT 1980, tie-in sales can be investigated by the OFFICE OF FAIR TRADING and (if necessary) by the COMPETITION COMMISSION, and prohibited if found to unduly restrict competition.
Collins Dictionary of Economics, 4th ed. © C. Pass, B. Lowes, L. Davies 2005