MOSCOW, June 2 (Reuters) - Russia’s Reserve Fund increased slightly to $16.50 billion as of June 1 from $16.34 billion a month earlier, finance ministry data showed on Friday.

The finance ministry also said the National Wealth Fund, which is designed to help balance the pension system, stood at $74.18 billion as of June 1, versus $73.57 billion as of May 1. (Reporting by Alexander Winning; editing by Maria Kiselyova)