The Commission is charged under Sections 3, 7 and 8 of this Act with preventing and eliminating unlawful tying contracts, corporate mergers and acquisitions, and interlocking directorates. This Act was amended by the Robinson-Patman Act, Pub. L. No. 74-692, 49 Stat. 1526, codified at 15 U.S.C. §§ 13, 13b, and 21a, under which the Commission is authorized to prevent certain practices involving discriminatory pricing and product promotion. The Hart-Scott-Rodino Act (HSR), adding Section 7A of the Clayton Act, is listed separately.