A private foundation that owns a small amount of stock in the News Corporation has written a letter to the company’s board objecting to its political contributions to Republican causes.

The Nathan Cummings Foundation, which promotes progressive causes, owns 3,820 shares of the News Corporation, with a value of about $52,000. The foundation is described on its Web site as being “rooted in the Jewish tradition and committed to democratic values and social justice, including fairness, diversity, and community.″

In the letter, obtained by The Caucus, the foundation calls for complete disclosure of all political spending by the News Corporation before Friday, when the company’s board of directors meets for its annual shareholders meeting.

The officials at Nathan Cummings note that their concerns were sparked by reports that Rupert Murdoch, the company’s chairman and chief executive, had directed the News Corporation to make $1 million donations to the U.S. Chamber of Commerce and the Republican Governors Association.

The letter reads, in part, “The apparent lack of a strategic rationale for News Corp. raises very serious concerns for shareholders as to whether Mr. Murdoch and the rest of the News Corp. Board of Directors are truly taking shareholder interests into account when they approve political payments made with shareholders’ assets.”

The letter concludes that without full disclosure, “there are clear reputational risks involved in political expenditures – particularly for a news media company – and unnecessary potential for abuse of corporate treasury funds to further the personal political agendas of corporate management.”

Teri Everett, a spokeswoman for the News Corporation, declined comment after receiving a copy of the letter.