Have you seen any reference to such claims being made in the secondary literature? Because I can't imagine any circumstances under which the Allies would entertain any claims for compensation by a defeated enemy for acts of war necessary to defeat that enemy.
And the number of German ships lost was pretty small compared to the Allied shipping losses, for reasons of simple geography. Given that the Allies never levied claims against Germany for individual shipping losses (though Germany was subject to other forms of reparations), I don't see them permitting Germany to do so. Any attempt would be laughed out of court even before the papers were filed.
You have to keep in mind that after the war, we occupied the country, split it up, and executed or imprisoned their most senior leadership. We weren't in the mood for compensating Germany for the expenses and losses associated with their aggression.
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We searched the National Archives Catalog and located 139 series, 4777 file units, and 87 items relating to I.G. Farben. In particular, we suggest reviewing records located in the Records of the U.S. High Commissioner for Germany (Record Group 466), Records of U.S. Occupation Headquarters, World War II (Record Group 260), and Records of the Office of Alien Property (Record Group 131). Please note that some of the records have been digitized and may be viewed online using the Catalog. For access to non-digitized records, please contact the unit listed in the description.
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