Antitrust: premerger notification.

Senator Umberg's Uniform Antitrust Premerger Notification Act establishes new state-level requirements for businesses filing federal premerger notifications under the Hart-Scott-Rodino Act. The legislation requires companies to submit copies of their federal merger documentation to California's Attorney General if they maintain their principal place of business in California or conduct at least 20% of their relevant annual sales within the state.

Under the new requirements, companies must electronically file their Hart-Scott-Rodino forms with the state within one business day of federal submission. Those headquartered in California must simultaneously provide all supplementary documentation, while companies meeting the sales threshold must furnish additional materials within seven business days if requested. The Attorney General may assess filing fees of $1,000 for California-based companies and $500 for others meeting the threshold.

The act includes strict confidentiality provisions that mirror federal protections, prohibiting public disclosure of submitted materials except in relevant administrative or judicial proceedings. The Attorney General may share information with federal antitrust authorities and with other states that have enacted equivalent laws with comparable confidentiality safeguards. Companies failing to comply with filing requirements face civil penalties up to $10,000 per day. The provisions apply to premerger notifications submitted after January 1, 2026.