CONCORD, N.H. — A New Hampshire auction house is offering a collection of documents from Oskar Schindler, the German industrialist who saved more than 1,000 Jewish workers at his factories during World War II, including a letter he signed that paved the way for the rescue chronicled in the 1993 movie “Schindler’s List.”

The letter, dated Aug. 22, 1944, describes permission to move his enamelware factory, workers included, out of Krakow, Poland, to Czechoslovakia, a move that historians say allowed him to save the workers....