SHANGHAI, Mar 22 (SMM) – Higher demand from infrastructure, and recovery of construction sites and steel mills continued to deplete rebar inventories in the week ended Thursday March 21, SMM data showed. Average prices of spot rebar increased by 51.2 yuan/mt week on week, to 3,962.9 yuan/mt as of Thursday March 21, as traders firmed up offers ahead of the lower value-added tax takes effect on April 1.  Overall inventories, including social and in-plant stocks, shrank to 11.72 million mt as of Thursday March 21, down 6.1% from a week ago and down 11.5% from a lunar year earlier, showed SMM data. This compared with a week-on-week decline of 5.8% on Thursday March 14.  As of March 21, inventories across steel mills stood at 2.55 million mt, down 8.4% from a week ago and down 31.2% from a lunar year ago. Social stocks also declined by 6% on the week and by 3.8% on the year to stand at 9.17 million mt as of March 21. For the same week, social inventories of long steel, including wire rods and rebar, in Guangzhou of Guangdong province extended gains by 0.46% from a week ago and stood at 1.96 million mt, SMM data showed.