opinion: Mr. Justice Clark
  delivered the opinion of the Court.
  This private treble-damage antitrust action was brought by the New Jersey Wood Finishing Company against Minnesota Mining and Manufacturing Company and the Essex Wire Corporation. Respondent’s original complaint was filed on November 20,1961. It alleged violations of § 7 of the Clayton Act, a conspiracy to restrain commerce in electrical insulation products in violation of § 1 of the Sherman Act and an attempt to monopolize the same as prohibited by § 2. The substance of the complaint concerned the acquisition in 1956 of all the assets of Insulation and Wires, Inc., a subsidiary of Essex, by Minnesota Mining and an alleged conspiracy to restrain trade in electrical insulation products. The latter claimed that the suit was barred by the four-year limitation provision of the Clayton Act. However, New Jersey Wood asserted that the bar of the statute had been tolled by a proceeding filed in 1960 against Minnesota Mining by the Federal Trade Commission under § 7 of the Clayton Act. That action resulted in a consent order under which Minnesota Mining was directed to divest itself of the assets acquired. Section 5 (b) of the Clayton Act provides that a “civil or criminal proceeding . . . instituted by the United States to prevent, restrain, or punish violations of any of the antitrust laws” suspends the running of the statute of limitations during the pendency thereof and for one year thereafter with respect to private actions arising under those laws and based on any matter complained of in the government suit. The questions here are whether proceedings by the Federal Trade Commission toll the running of the § 4B statute of limitations to the same extent as do judicial proceedings and, if they do, whether the claim of New Jersey Wood is based on “any matter complained of” in the Commission action. The District Court denied Minnesota Mining’s motion to dismiss, holding that the four-year statute had been tolled by § 5 (b) and that this suit was timely filed. 216 F. Supp. 507. The Court of Appeals affirmed. 332 F. 2d 346. We granted certiorari because of a conflict between circuits and the importance of the question in the administration of the Clayton Act. 379 U. S. 877.
  I.
  New Jersey Wood is engaged in the manufacture of electrical insulation materials, some of which it sells to independent distributors who, in turn, sell to wire and cable manufacturers and fabricators. Minnesota Mining is a diversified company, with one of its divisions producing electrical insulation materials. Essex is a substantial consumer of electrical insulation material. It owned Insulation Wires which distributes that type of material.
  In August 1956 Minnesota Mining bought all the assets of Insulation Wires and in 1960 the Federal Trade Commission filed a proceeding against it under § 7 of the Clayton Act which resulted in a consent order directing the divestiture by Minnesota Mining of the assets so acquired. This order was dated August 24, 1961. The Commission charged that prior to 1953 Minnesota Mining was the leading manufacturer of electrical insulation tape; that through five transactions in the years 1952 through 1956 it had also brought under its control substantial shares of other major electrical product lines; and that its subsequent acquisition of two of the three largest distributors of these products might have the effect of actually or potentially lessening competition and tending to create a monopoly in various aspects of that commerce. One of the two distributors so acquired was Insulation Wires.
  Thereafter, within a year, this suit was filed. We need not detail the allegations of the complaint. It is sufficient to say that the gist of it was that prior to August 1956 Insulation Wires was the primary distributor of New Jersey Wood products throughout the United States; that in August 1956 Minnesota Mining acquired all of the assets of Insulation Wires and during the next month notified New Jersey Wood that beginning in January 1957 Insulation Wires would no longer distribute its products. The complaint also charged Minnesota Mining and Essex with conspiring to restrain trade and commerce in the manufacture, sale and distribution of electrical insulation products beginning with the acquisition of Insulation Wires and continuing until the filing of this suit. There were numerous overt acts alleged as being in furtherance of the conspiracy, the first of which was that acquisition.
  h-i H-Í
  At the outset it is necessary to examine § 5 (a) of the Clayton Act and its relationship to § 5 (b). The former makes a final judgment or decree in any civil or criminal proceeding brought by or on behalf of the United States prima facie evidence in subsequent private suits “as to all matters respecting which said judgment or decree would be an estoppel as between the parties thereto.” Several distinctions between these sections are apparent and suggest that they are not wholly interdependent. First, the words “final judgment or decree” are used in § 5 (a) and are of crucial significance in its application. However, § 5 (b) tolls the statute of limitations set out in § 4B from the time suit is instituted by the United States regardless of whether a final judgment or decree is ultimately entered. Its applicability in no way turns on the success of the Government in prosecuting its case. Moreover, under § 5 (a) the judgment or decree may be used only as to matters respecting which it would operate as an estoppel between the parties. No such limitation appears in the tolling provision. It applies to every private right of action based in whole or in part on “any matter” complained of in the government suit.
  When we turn from the express language of these two statutory provisions to the congressional policies underlying them, it becomes even more apparent that the applicability of § 5 (a) to Federal Trade Commission actions should not control the question whether such proceedings toll the statute of limitations. We have discussed these policies at greater length below. At this juncture it is sufficient to say that in framing § 5 (a) Congress focused on the narrow issue of the use by private parties of judgments or decrees as prima facie evidence. This was recognized in Emich Motors Corp. v. General Motors Corp., 340 U. S. 558 (1951), where we stated that the purpose of § 5 (a) was “to minimize the burdens of litigation for injured private suitors by making available to them all matters previously established by the Government in antitrust actions” and to permit them “as large an advantage as the estoppel doctrine would afford had the Government brought suit.” Id., at 568. As we shall show, however, its purpose in adopting § 5 (b) was not so limited, for it was not then dealing with the delicate area in which a judgment secured in an action between two parties may be used by a third. Whatever ambiguities may exist in the legislative history of these provisions as to other questions, it is plain that in § 5 (b) Congress meant to assist private litigants in utilizing any benefits they might cull from government antitrust actions. See S. Rep. No. 619, 84th Cong., 1st Sess., 6. The distinction was emphasized in Union Carbide & Carbon Corp. v. Nisley, 300 F. 2d 561 (1962), where the court, after noting the analysis of § 5 (a) set out in Emich Motors Corp., supra, stated that:
  “The corollary purpose of the tolling provisions of the second paragraph of Section 5 [now § 5 (b) ] is to vouchsafe the intended benefits of related government proceedings by suspending the running of the statute of limitations until the termination of the government proceedings, and allowing the private suitor one year thereafter in which to prepare and file his suit. The competency of a government judgment in a private suit is necessarily restricted to the requirements of due process. But the tolling of the statute during the pendency of the government litigation is not so limited.” Id., at 569.
  In our view, therefore, the two sections are not necessarily coextensive; they are governed by different considerations as well as congressional policy objectives. This makes § 5 (b) readily severable from § 5 (a). Even if we assumed arguendo that § 5 (a) is inapplicable to Commission proceedings — a question upon which we venture no opinion — that conclusion would be immaterial in our consideration of § 5 (b) and § 4B. Congress has expressed its belief that private antitrust litigation is one of the surest weapons for effective enforcement of the antitrust laws. This construction will lend considerable impetus to that policy.
  III.
  Section 5, later §§ 5 (a) and 5 (b), was passed in response to the plea of President Wilson. In a speech to the Congress on January 20, 1914, he urged that a law be enacted which would permit victims of antitrust violations to have “redress upon the facts and judgments proved and entered in suits by the Government” and that “the statute of limitations ... be suffered to run against such litigants only from the date of the conclusion of the Government’s action.” 51 Cong. Rec. 1964. The broad aim of this enactment was to use “private self-interest as a means of enforcement” of the antitrust laws. Bruce’s Juices, Inc. v. American Can Co., 330 U. S. 743, 751 (1947). The “entire provision [was] intended to help persons of small means who are injured in their property or business by combinations or corporations violating the antitrust laws.” H. R. Rep. No. 627, 63d Cong., 2d Sess., 14. See S. Rep. No. 619, supra, at 6.
  It may be, as Minnesota Mining contends, that when it was enacted the tolling provision was a logical backstop for the prima facie evidence clause of § 5 (a). But even though § 5 (b) complements § 5 (a) in this respect by permitting a litigant to await the outcome of government proceedings and use any judgment or decree rendered therein- — a benefit which often is of limited practical value- — it is certainly not restricted to that effect. As we have pointed out, the textual distinctions as well as the policy basis of § 5 (b) indicate that it was to serve a more comprehensive function in the congressional scheme of things. The Government’s initial action may aid the private litigant in a number of other ways. The pleadings, transcripts of testimony, exhibits and documents are available to him in most instances. In fact, the rules of the Commission so provide. 16 CFR § 1.132 (e). See generally 16 CFR § 1.131 et seq. Moreover, difficult questions of law may be tested and definitively resolved before the private litigant enters the fray. The greater resources and expertise of the Commission and its staff render the private suitor a tremendous benefit aside from any value he may derive from a judgment or decree. Indeed, so useful is this service that government proceedings are recognized as a major source of evidence for private parties. See Bicks, The Department of Justice and Private Treble Damage Actions, 4 Antitrust Bull. 5 (1959); Loevinger, Handling a Plaintiff’s Antitrust Damage Suit, 4 Antitrust Bull. 29 (1959).
  Admittedly, there is little in the legislative history to suggest that Congress consciously intended to include Commission actions within the sweep of the tolling provision. But neither is there any substantial evidence that it consciously intended to exclude them. The fact of the matter is that the record of the 1914 legislative proceedings reveals an almost complete absence of any discussion on the tolling problem. It seems that Congress simply did not consider the extent of its coverage in the course of its deliberations.
  It is in light of this legislative silence that we must determine whether § 4B is tolled by Commission proceedings. In resolving this question we must necessarily rely on the one element of congressional intention which is plain on the record — the clearly expressed desire that private parties be permitted the benefits of prior government actions. Implicit in such an objective is the necessity that the tolling provision include Commission proceedings. Otherwise the benefits flowing from a major segment of the Government’s enforéement effort would, in many cases, be denied to private parties. In this connection, and of crucial significance, is the fact that the potential advantages available to such litigants because of § 5 (b) reach far beyond the specific and limited benefits accruing to them under § 5 (a). Furthermore, the § 5 (b) advantages flow as naturally from Commission proceedings as they do from Justice Department actions. Yet petitioner contends that § 4B must be tolled in the latter but not in the former. Such a grudging interpretation of the interrelationship of § 5 (b) and § 4B, however, would collide head-on with Congress’ basic policy objectives. Acceptance of petitioner’s position would make enjoyment of these intended benefits turn on the arbitrary allocation of enforcement responsibility between the Department and the Commission, and we must therefore reject it.
  It is true that the precise language of § 5 (b) does not clearly encompass Commission proceedings. But it is not the literal wording of such a provision that is controlling where, as here, Congress has evidenced neither acceptance nor rejection of either interpretation, yet one effects a clearly expressed congressional purpose while the other defeats it. We stated the pivotal question for determination in such an event only this Term in Burnett v. New York Central R. Co., 380 U. S. 424, 427 (1965): “[WJhether congressional purpose is effectuated by tolling the statute of limitations in given circumstances.” In order to determine that intent, we must examine “the purposes and policies underlying the limitation provision, the Act itself, and the remedial scheme developed for the enforcement of the rights given by the Act.” Ibid. Guided by these criteria, we think it clear that congressional policy sustaining § 5 (b) would be effectively served only by tolling the statute of limitations in cases such as this, and we deem that policy controlling. This analysis is not a novel one. Mr. Justice Holmes, sitting on circuit, noted in Johnson v. United States, 163 F. 30, 32:
  “A statute may indicate or require as its justification a change in the policy of the law, although it expresses that change only in the specific cases most likely to occur to the mind. The Legislature has the power to decide what the policy of the law shall be, and if it has intimated its will, however indirectly, that will should be recognized and obeyed. The major premise of the conclusion expressed in a statute, the change of policy that induces the enactment, may not be set out in terms, but it is not an adequate discharge of duty for courts to say: We see what you are driving at, but you have not said it, and therefore we shall go on as before.”
  We hold, therefore, that the limitation provision of § 4B is tolled by Commission proceedings to the same extent and in the same circumstances as it is by Justice Department actions. In so holding we give effect to Congress’ basic policy objectives in enacting § 5 (b) — objectives which would be frustrated should we reach a contrary conclusion and thereby deprive large numbers of private litigants of the benefits of government antitrust suits simply because those suits were pursued by one governmental agency rather than the other.
  IV.
  Minnesota Mining further contends that even though § 5 (b) tolls Commission proceedings, the suit here, insofar as it asserts Sherman Act claims, is not based in part on any matter complained of in the Commission’s proceeding. We cannot agree.
  New Jersey Wood’s Sherman Act claims rest on an alleged conspiracy to restrain and attempt to monopolize trade and commerce in the manufacture, sale and distribution of electrical insulation products. The purposes of the conspiracy were alleged to be: (1) to control Insulation Wires; (2) to prevent' it from distributing New Jersey Wood products; (3) to insure that Insulation Wires’ supplies were purchased from a Minnesota Mining subsidiary; (4) to effect tie-in sales of electrical insulation products with other Minnesota Mining products; and (5) to have Essex deal only with Insulation Wires in purchasing electrical insulation products to the exclusion of competitive distributors handling New Jersey Wood products. The effect of the conspiracy was alleged to be the complete disruption of the pattern of manufacture, sale and distribution that New Jersey Wood had enjoyed with Insulation Wires and denial to it of access to substantial national markets for electrical insulation products.
  Certain ly the allegations are based “in part” on the Commission action. It charged that the Insulation Wires acquisition, along with that of another distributor, placed in the hands of Minnesota Mining, a manufacturer, two of the three largest distributors in the business; that following the acquisitions these distributors discontinued distribution of the products of a number of manufacturers who had used them prior to their acquisition by Minnesota Mining; and that the effect of such action by Minnesota Mining was “the actual or potential lessening of competition” in the manufacture, sale and distribution of insulation products and the foreclosure of other manufacturers from a substantial share of the markets for said products. It appears to us that both suits set up substantially the same claims. It is true that the Commission’s Clayton Act proceeding required proof only of a potential anticompetitive effect while the Sherman Act carries the more onerous burden of proof of an actual restraint. The Commission complaint, however, did allege an “actual” as well as a “potential” lessening of competition, i. e., manufacturers “have been foreclosed from a substantial share of the markets.” Moreover, the monopolization count was phrased in terms of an “attempt to monopolize,” which may be illegal though not successful. See United States v. Columbia Steel Co., 334 U. S. 495, 525, 531-532 (1948).
  Minnesota Mining’s claim seems to be that the crucial difference between the Commission and the New Jersey Wood proceedings is that the former alleges conduct that may substantially lessen competition while the latter asserts activity that has actually done so. We think that this is a distinction without a difference and does not deprive New Jersey Wood of the tolling effect of § 5 (b). That clause provides for tolling as long as the private claim is based “in part on any matter complained of” in the government proceedings. The fact that New Jersey Wood claims that the same conduct has a greater anti-competitive effect does not make the conduct challenged any less a matter complained of in the government action. It merely requires it to meet a greater burden of proof as to the effect of the conspiracy before a Sherman Act claim can be sustained.
  Affirmed.
  Mr. Justice Harlan and Mr. Justice Stewart did not participate in the decision of this case.
  The case was considered on interlocutory appeal. 28 U. S. C. § 1292 (b) (1958 ed.). Essex did not appeal and is not a party here.
  During the pendency of the case in the District Court respondent filed an amended complaint. However, respondent’s theories of recovery and the controlling legal questions are common to both pleadings.
  38 Stat. 731, as amended, 15 U. S. C. § 18 (1964 ed.).
  26 Stat. 209, as amended, 15 U. S. C. §§ 1, 2 (1964 ed.).
  Section 4B of the Clayton Act, 69 Stat. 283, 15 U. S. C. § 15b (1964 ed.), provides that:
  “Any action to enforce any cause of action under sections 15 or 15a of this title shall be forever barred unless commenced within four years after the cause of action accrued. No cause of action barred under existing law on the effective date of this section and sections 15a and 16 of this title shall be revived by said sections.”
  Section 5 (b), 38 Stat. 731, as amended, 15 U. S. C. § 16 (b) (1964 ed.), provides:
  “(b) Whenever any civil or criminal proceeding is instituted by the United States to prevent, restrain, or punish violations of any of the antitrust laws, but not including an action under section 15a of this title, the running of the statute of limitations in respect of every private right of action arising under said laws and based in whole or in part on any matter complained of in said proceeding shall be suspended during the pendency thereof and for one year thereafter: Provided, however, That whenever the running of the statute of limitations in respect of a cause of action arising under section 15 of this title is suspended hereunder, any action to enforce such cause of action shall be forever barred unless commenced either within the period of suspension or within four years after the cause of action accrued.”
  See Highland Supply Corp. v. Reynolds Metals Co., 327 F. 2d 725 (C. A. 8th Cir. 1964).
  Section 5 (a), 38 Stat. 731, as amended, 15 U. S. C. §16 (a) (1964 ed.), provides:
  “(a) A final judgment or decree heretofore or hereafter rendered in any civil or criminal proceeding brought by or on behalf of the United States under the antitrust laws to the effect that a defendant has violated said laws shall be prima facie evidence against such defendant in any action or proceeding brought by any other party against such defendant under said laws or by the United States under section 15a of this title, as to all matters respecting which said judgment or decree would be an estoppel as between the parties thereto: Provided, That this section shall not apply to consent judgments or decrees entered before any testimony has been taken or to judgments or decrees entered in actions under section 15a of this title.”
  See Theatre Enterprises, Inc. v. Paramount Film Distributing Corp., 346 U. S. 537 (1954).