delivered the opinion of the Court.
In this ease we ask whether the antitrust rule that group boycotts are illegal
per se
as set forth in
Klor’s, Inc.
v.
Broadway-Hale Stores, Inc.,
í — I
Before 1984 American Telephone and Telegraph Company (AT&T) supplied most of the Nation’s telephone service and, through wholly owned subsidiaries such as Western Electric, it also supplied much of the Nation’s telephone equipment. In 1984 an antitrust consent decree took AT&T out of the
local
telephone service business and left AT&T a
long-distance
telephone service provider, competing with such firms as MCI and Sprint. See M. Kellogg, J. Thorne, & P. Huber, Federal Telecommunications Law §4.6, p. 221
*131
(1992). The decree transformed AT&T's formerly owned local telephone companies into independent firms. At the same time, the decree insisted that those local firms help assure competitive long-distance service by guaranteeing long-distance companies physical access to their systems and to their local customers. See
United States
v.
American Telephone & Telegraph Co.,
Diseon, Inc., the respondent, sold removal services used by New York Telephone Company, a firm supplying local telephone service in much of New York State and parts of Connecticut. New York Telephone is a subsidiary of NYNEX Corporation. NYNEX also owns Materiel Enterprises Company, a purchasing entity that bought removal services for New York Telephone. Diseon, in a lengthy detailed complaint, alleged that the NYNEX defendants (namely, NYNEX, New York Telephone, Materiel Enterprises, and several NYNEX related individuals) engaged in unfair, improper, and anticompetitive activities in order to hurt Diseon and to benefit Discon’s removal services competitor, AT&T Technologies, a lineal descendant of Western Electric. The Federal District Court dismissed Discon’s complaint for failure to state a claim. The Court of Appeals for the Second Circuit affirmed that dismissal with an exception, and that exception is before us for consideration.
The Second Circuit focused on one of Discon’s specific claims, a claim that Materiel Enterprises had switched its purchases from Diseon to Discon’s competitor, AT&T Tech *132 nologies, as part of an attempt to defraud local telephone serviee customers by hoodwinking regulators. According to Discon, Materiel Enterprises would pay AT&T Technologies more than Discon would have charged for similar removal services. It did so because it could pass the higher prices on to New York Telephone, which in turn could pass those prices on to telephone consumers in the form of higher regulatory-agency-approved telephone service charges. At the end of the year, Materiel Enterprises would receive a special rebate from AT&T Technologies, which Materiel Enterprises would share with its parent, NYNEX. Discon added that it refused to participate in this fraudulent scheme, with the result that Materiel Enterprises would not buy from Discon, and Discon went out of business.
These allegations, the Second Circuit said, state a cause of action under §1 of the Sherman Act, though under a “different legal theory” from the one articulated by Discon.
*133
The Second Circuit noted that the Courts of Appeals are uncertain as to whether, or when, the
per se
group boycott rule applies to a decision by a purchaser to favor one supplier over another (which the Second Circuit called a “two-firm group boycott”). Compare
Com-Tel, Inc.
v.
DuKane Corp.,
II
As this Court has made clear, the Sherman Act’s prohibition of “[e]very” agreement in “restraint of trade,” 26 Stat. 209, as amended, 15 U. S. C. § 1, prohibits only agreements that
unreasonably
restrain trade. See
Business Electronics Corp.
v.
Sharp Electronics Corp.,
The Court has found the
per se
rule applicable in certain group boycott eases. Thus, in
Fashion Originators’ Guild of America, Inc.
v.
FTC,
In
Klor’s
the Court also applied the
per se
rule. The Court considered a boycott created when a retail store, Broadway-Hale, and 10 household appliance manufacturers and their distributors agreed that the distributors would not sell, or would sell only at discriminatory prices, household appliances to Broadway-Hale’s small, nearby competitor, namely, Klor’s.
The case before us involves Klor’s. The Second Circuit did not forbid the defendants to introduce evidence of “justification.” To the contrary, it invited the defendants to do so, for it said that the “per se rule” would apply only if no “pro-competitive justification” were to be found. 93 E 3d, at 1061; cf. 7 P. Areeda & H. Hovenkamp, Antitrust Law f 1510, p. 416 (1986) (“Boycotts are said to be unlawful per se but justifications are routinely considered in defining the forbidden category”)- Thus, the specific legal question before us is whether an antitrust court considering an agreement by a buyer to purchase goods or services from one supplier rather than another should (after examining the buyer’s reasons or justifications) apply the per se rule if it finds no legitimate business reason for that purchasing decision. We conclude no boycott-related per se rule applies and that the plaintiff here must allege and prove harm, not just to a single competitor, but to the competitive process, i. e., to competition itself.
Our conclusion rests in large part upon precedent, for precedent limits the
per se
rule in the boycott context to cases involving horizontal agreements among direct competitors. The agreement in
Fashion Originators’ Guild
involved what may be called a group boycott in the strongest sense: A group of competitors threatened to withhold business from third parties unless those third parties would help them injure their directly competing rivals. Although
Klor’s
involved a threat made by a
single
powerful firm, it also involved a horizontal agreement among those threatened, namely, the appliance suppliers, to hurt a competitor of the retailer who made the threat. See
“not a ease of a single trader refusing to deal with, another, nor even of a manufacturer and a dealer agreeing to an exclusive distributorship. Alleged in this complaint is a wide combination consisting of manufacturers, distributors and a retailer.”859 U. S., at 212-213 (footnote omitted).
This Court subsequently pointed out specifically that
Klor’s
was a ease involving not simply a “vertical” agreement between supplier and customer, but a case that also involved a “horizontal” agreement among competitors. See
Business Electronics,
We have not found any special feature of this case that could distinguish it from the precedent we have just discussed. We concede Diseon’s claim that the petitioners’ behavior hurt consumers by raising telephone service rates. But that consumer injury naturally flowed not so much from a less competitive market for removal services, as from the exercise of market power that is lawfully in the hands of a monopolist, namely, New York Telephone, combined with a deception worked upon the regulatory agency that prevented the agency from controlling New York Telephone’s exercise of its monopoly power.
To apply the
per se
rule here — where the buyer’s decision, though not made for competitive reasons, composes
*137
part of a regulatory fraud — would transform eases involving business behavior that is improper for various reasons, say, cases involving nepotism or personal pique, into treble-damages antitrust eases. And that
per se
rule would discourage firms from changing suppliers — even where the competitive process itself does not suffer harm. Cf.
Poller
v.
Columbia Broadcasting System, Inc.,
The freedom to switch suppliers lies close to the heart of the competitive process that the antitrust laws seek to encourage. Cf.
Standard Oil,
Discon points to another special feature of its complaint, namely, its claim that Materiel Enterprises hoped to drive Discon from the market lest Diseon reveal its behavior to New York Telephone or to the relevant regulatory agency. That hope, says Discon, amounts to a special anticompeti-tive motive.
*138 We do not see how the presence of this special motive, however, could make a significant difference. That motive does not turn Materiel Enterprises’ actions into a “boycott” within the meaning of this Court’s precedents. See supra, at 135-136. Nor, for that matter, do we understand how Diseon believes the motive affected Materiel Enterprises’ behavior. Why would Discon’s demise have made Diseon’s employees less likely, rather than more likely, to report the overcharge/rebate scheme to telephone regulators? Regardless, a per se rule that would turn upon a showing that a defendant not only knew about but also hoped for a firm’s demise would create a legal distinction — between corporate knowledge and corporate motive — that does not necessarily correspond to behavioral differences and which would be difficult to prove, making the resolution of already complex antitrust cases yet more difficult. We cannot find a convincing reason why the presence of this special motive should lead to the application of the per se rule.
Finally, we shall consider an argument that is related tangentially to Discon’s per se claims. The complaint alleges that New York Telephone (through Materiel Enterprises) was the largest buyer of removal services in New York State, see Amended Complaint ¶¶2, 29, 99, App. 75, 83, 110, and that only AT&T Technologies competed for New York Telephone’s business, see ¶¶2, 26, 29, id., at 75, 82-83. One might ask whether these accompanying allegations are sufficient to warrant application of a Klor’s-type presumption of consequent harm to the competitive process itself.
We believe that these allegations do not do so, for, as we have said, see
supra,
at 135-136, antitrust law does not permit the application of the
per se
rule in the boycott context in the absence of a horizontal agreement, though in other contexts, say, vertical price fixing, conduct may fall within the scope of a
per se
rule not at issue here, see,
e. g., Dr. Miles Medical Co.,
1 — 4 h-i í — l
The Court of Appeals also upheld the complaint’s charge of a conspiracy to monopolize in violation of §2 of the Sherman Act. It did so, however, on the understanding that the conspiracy in question consisted of the very same purchasing practices that we have previously discussed. Unless those agreements harmed the competitive process, they did not amount to a conspiracy to monopolize. We do not see, on the basis of the facts alleged, how Discon could succeed on this claim without prevailing on its §1 claim. See 3 Areeda & Hovenkamp, supra, ¶ 651e, at 81-82. Given our conclusion that Discon has not alleged a § 1 per se violation, we think it prudent to vacate this portion of the Court *140 of Appeals’ decision and allow the court to reconsider its finding of a §2 claim.
IV
Petitioners ask us to reach beyond the “per se” issues and to hold that Discon’s complaint does not allege anywhere that their purchasing decisions harmed the competitive process itself and, for this reason, it should be dismissed. They note that Discon has not pointed to any paragraph of the complaint that alleges harm to the competitive process. This matter, however, lies outside the questions presented for certiorari. Those questions were limited to the application of the per se rule. For that reason, we believe petitioners cannot raise that argument in this Court.
V
For these reasons, the judgment of the Court of Appeals is vacated, and the case is remanded for further proceedings consistent with this opinion.
It is so ordered.
