Jan 8 (Reuters) - The U.S. Supreme Court on Monday declined to hear R.J. Reynolds Tobacco Company's challenge to a voter-approved measure in California that banned flavored tobacco products in the most-populous U.S. state.

The justices rejected an appeal by R.J. Reynolds, a unit of British American Tobacco, and other plaintiffs of a lower court's ruling holding that California's law did not conflict with a federal statute regulating tobacco products.

(Reporting by Nate Raymond in Boston; Editing by Alexia Garamfalvi, Daniel Wallis and Will Dunham)