US December factory ISM revised to 63.4 from 66.2 Monday January 26, 10:21 am ET NEW YORK, Jan 26 (Reuters) - NEW YORK, Jan 26 (Reuters) - The Institute for Supply Management on Monday said December manufacturing and non-manufacturing growth were slower than previously reported. As a part of its annual revisions going back four years, ISM revised the December reading for its factory survey lower, to 63.4 from 66.2. ISM's non-manufacturing gauge for last month was only slightly affected by the changes, which took the figure to 58.0 from the 58.6 originally reported. US ISM Index annual manufacturing revisions...