new delhi, Aug. 22 -- India's private sector growth appears set to pick up moderately in August after slowing to a more than four-year low in July, according to preliminary data from the HSBC Flash India Purchasing Managers' Index (PMI) released on Friday. The HSBC Flash India Composite PMI Output Index rose to 54.6 in August from July's 52-month low of 54.3, signalling a modest improvement in private-sector activity, the survey compiled by S&P Global showed. The flash reading pointed to a quicker upturn in services, while manufacturing growth remained subdued. The services index is estimated at 54.5 in August against 53.3 in July. However, the manufacturing PMI output index for the month is estimated to contract sharply from 56.4 in July t...