The photographic AGK3 work at the Hamburg Observatory has progressed so far that the measurements for the entire Bergedorf part of 1219 fields and approximately one-half of the Bonn part of 720 fields have been completed. For the measured plates the relative proper motions have been obtained differentially by comparison of AGK3 and AGK2 measurements, making allowance for color-magnitude equations of the objectives and the systematic errors in the AGK2 positions. The derivation of absolute proper motions in the system of the reference stars will be made after the definitive positions of the reference stars AGK3R become available. In order to decide on the procedure to be followed in this part of the work experiments were made with selected representative fields. These trial solutions indicate that a more satisfactory result is obtained if the final solution for each field is based upon the measurements of the central plate and four partially overlapping neighboring plates rather than upon a single plate. The advantage of this procedure is in the smoothing of the accidental errors in the reference stars on the central plate. A secondary advantage is the strengthening of the solution for fields with a poor distribution of the reference stars.