To strengthen the Foreign Agents Registration Act of 1938, as amended.

Amends the Foreign Agents Registration Act of 1938 to declare that a foreign principal shall be considered to control a person in major part if: (1) such principal holds more than 50 percent of equitable ownership in such person; or (2) such principal, subject to rebuttal evidence, holds at least 20 percent but not more than 50 percent of equitable ownership in such person.

Requires agents of foreign principals who have filed registration statements to file supplements to such statements with the Attorney General on January 31 and July 31 of each year. Authorizes agents with accounting systems using different fiscal years to petition the Attorney General to permit the filing of statements at the close of the first and seventh month of such fiscal year in lieu of the required dates.

Provides that the exemption from the foreign agent registration requirement for individuals providing legal representation for a foreign principal before a U.S. agency shall apply only to representation before the Patent and Trademark Office.

Imposes civil penalties upon persons who have: (1) failed to file registration statements; or (2) omitted a material fact or made false statements on registration statements.

Authorizes the Attorney General to serve civil investigative demands on persons in control of material relevant to investigations concerning violations of registration requirements.