Editing United States antitrust law (section)

==Mergers==
{{see also|Mergers and acquisitions|Merger control}}

Under Section 7 of the Clayton Act, a merger or acquisition is illegal if its effect "may be substantially to lessen competition, or to tend to create a monopoly." 
{{Quote 
|text=No person engaged in commerce or in any activity affecting commerce shall acquire, directly or indirectly, the whole or any part of the stock or other share capital and no person subject to the jurisdiction of the Federal Trade Commission shall acquire the whole or any part of the assets of another person engaged also in commerce or in any activity affecting commerce, where in any line of commerce or in any activity affecting commerce in any section of the country, the effect of such acquisition may be substantially to lessen competition, or to tend to create a monopoly.
|source=Clayton Act, section 7 ({{UnitedStatesCode|15|18}})
}}
The FTC and the Justice Department both have the authority to file lawsuits seeking to block or invalidate a merger. The FTC may challenge a merger in its own administrative court instead of filing a lawsuit in a [[United States district court]], although defendants can appeal the FTC's decisions to one of the [[United States courts of appeals]]. A private party may also file a lawsuit under the Clayton Act if an unlawful merger has injured its ability to compete for business. 

Under the [[Hart–Scott–Rodino Antitrust Improvements Act|Hart–Scott–Rodino (HSR) Act of 1976]], if a proposed merger and the parties executing it are both above certain sizes, then the parties must report it in advance to the FTC and the Justice Department. The parties must then wait 30 days while the FTC or the Justice Department reviews the merger and decides whether to seek to block it. The 30-day period usually ends with the FTC or Justice Department taking one of three actions: declining to challenge the merger, filing a lawsuit to challenge the merger, or issuing a "Second Request" that extends the waiting period and formally asks the party for all its documents and other information relating to the merger.

===Horizontal mergers===
{{Slist mergers}}
{{see also|Horizontal integration}}
*''[[Northern Securities Co. v. United States]]'', {{ussc|193|197|1904}} horizontal merger under the Sherman Act
*''[[United States v. Philadelphia National Bank]]'', {{ussc|374|321|1963}} the second and third largest of 42 banks in the Philadelphia area would lead to a 30% market control in a concentrated market, and so violated the Clayton Act §7. Banks were not exempt even though there was additional legislation under the [[Bank Merger Act of 1960]].
*''[[United States v. Von's Grocery Co.]]'', 384 U.S. 270 (1966) a merger of two grocery firms in the [[Los Angeles]] area did violate the Clayton Act §7, particularly considering the amendment by the [[Celler–Kefauver Act]] 1950
*''United States v. General Dynamics Corp.'', 415 U.S. 486 (1974) General Dynamics Corp had taken control over, by share purchase, United Electric Coal Companies, a strip-mining coal producer.
*[[Horizontal Merger Guidelines]] (2010)
*''[[FTC v. Staples, Inc.]]'', 970 F. Supp. 1066 (1997)
*''[[Hospital Corp. of America v. FTC]]'', 807 F. 2d 1381 (1986)
*''[[Federal Trade Commission v. H.J. Heinz Co.]]'', 246 F.3d 708 (2001)
*''[[United States v. Oracle Corp]]'', 331 F. Supp. 2d 1098 (2004)

===Vertical mergers===
{{see also|Vertical integration}}
*''[[United States v. Columbia Steel Co.]]'', {{ussc|334|495|1948}}
*''[[United States v. E.I. Du Pont De Nemours & Co.]]'', {{ussc|351|377|1956}}
*''[[Brown Shoe Co., Inc. v. United States]]'', {{ussc|370|294|1962}} there is not one single test for whether a merger substantially lessens competition, but a variety of economic and other factors may be considered. Two shoe retailers and manufacturers merging was held to substantially lessen competition, given the market in towns over 10,000 people for men's, women's and children's shoes.

===Conglomerate mergers===
{{See also|Conglomerate merger}}
*''[[United States v. Sidney W. Winslow]]'', {{ussc|227|202|1913}}
*''[[United States v. Continental Can Co.]]'', {{ussc|378|441|1964}} concerning the definition of the market segments in which the Continental Can Co was performing a merger.
*''[[FTC v. Procter & Gamble Co.]]'', {{ussc|386|568|1967}}