The following principal federal regulations govern public takeovers:
• Sections 14(d) and (e) of the Exchange Act, governing tender and exchange offers.

• Section 13(d) of the Exchange Act, requiring the disclosure of an acquisition of 5% of a class of voting equity in a public company.

• Regulations 14A and 14C of the Exchange Act, governing solicitations of shareholders in proxy contests and consent solicitations (for companies that allow shareholders to act by written consent in lieu of a formal vote at a shareholders' meeting) for the control of a public company's board of directors. A proxy contest usually occurs in the context of a hostile takeover, where the bidder attempts to convince shareholders to use their proxy votes to install new board members and/or management that are open to the takeover.

• Registration requirements of the Securities Act, requiring companies proposing to offer or sell securities to register the securities offered in the transaction, unless an exemption applies.

• Rule 13e-3 of the Exchange Act, regulating public to private transactions in which existing shareholders or affiliates of a company squeeze out its public shareholders.

The SEC usually enforces the federal securities laws and regulations, but opposing parties in a hostile takeover and shareholders can also bring an action on their own behalf. Acquisitions of US companies (or foreign companies with significant US interests) must also comply with the anti-trust filing and waiting period requirements of the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (HSR Act) (see Question 25).