U.S. nonfarm productivity rose the most in nearly four years in the third quarter, but a drop in unit labor costs underlined a lack of inflation pressure, Reuters reported. Productivity rose at a 3 percent annual rate after increasing at a 1.8 percent pace in the second quarter, the U.S. Labor Department said today, driven by a 4.7 percent rise in output. The data revised up an earlier estimate and was slightly above the 2.8 percent increase analysts forecast in a Reuters poll.