Subdued after key economic data showed a slowdown in manufacturing activity for the last month, a barometer of the Indian equity markets provisionally closed flat on Thursday.The barometer 30-scrip sensitive index (S&P Sensex) of the Bombay Stock Exchange had previously on Wednesday closed with gains of 376 points or 1.46 percent.Initially on Thursday, the markets made healthy gains and continued their upward trajectory on the back of Tuesday's monetary easing by the Reserve Bank of India (RBI), supportive Asian markets and strengthening rupee value.However, the upward momentum lost its steam as the latest Nikkei India Manufacturing PMI (Purchasing Manufacturers Index) for the last month showed a contraction.The PMI was at a seven-month low of 51.2 in September. The wider 50-scrip Nifty of the National Stock Exchange (NSE) also provisionally ended the day's trade on a flat note. It closed marginally down by 1.10 points or 0.01 percent at 7,947.80 points.The S&P BSE Sensex which opened at 26,344.19 points, provisionally closed at 26,196.41 points (3.30 p.m.) -- 41.58 points or 0.16 percent up from the previous day's close at 26,154.83 points.The Sensex touched a high of 26,431.80 points and a low of 26,168.71 points in the intra-day trade.