By Lucia Mutikani WASHINGTON (Reuters) -U.S. worker productivity rebounded at a bit faster pace than initially thought in the third quarter, though the trend remained weak, keeping labor costs elevated. Economists said the report from the Labor Department on Wednesday pointed to inflation staying high and the Federal Reserve continuing to raise interest rates for some time. The U.S. central bank is in the midst of its fastest monetary policy tightening cycle since the 1980s as it fights to bring inflation back to its 2% target. “While not the timeliest measure, the recent strength in unit labo…