China\'s manufacturing activity expanded in September to a six-month high, HSBC said, a further sign that a rebound in the world\'s second-largest economy is gaining momentum on improving demand. The British banking giant\'s preliminary purchasing managers\' index (PMI) for September hit 51.2, the highest since March when it stood at 51.6, HSBC said in a statement. The result was higher than last month\'s final reading of 50.1, which had improved from an 11-month low of 47.7 in July and ended three months of contraction, according to the bank. The index tracks manufacturing activity in China\'s factories and workshops and is a closely watched gauge of the health of the world\'s second-largest economy. A reading below 50 indicates contraction, while anything above signals expansion. The September figure suggested China\'s ongoing growth rebound is consolidating on the back of \"simultaneous improvements\" in overseas and domestic demand, HSBC economist Qu Hongbin said in the release. \"We expect a more sustained recovery as the further filtering-through of fine-tuning measures should lift domestic demand,\" he said. \"This will create more favourable conditions to push forward reforms, which should in turn boost mid- and long-term growth outlooks.\" Chinese authorities have so far been reluctant to introduce large-scale stimulus measures, but in late July did announce some steps to boost growth, such as reducing taxes on small companies and encouraging railway development. The first half of this year saw analyst concerns about China\'s economy mount after an expected rebound from growth of 7.7 percent last year -- the worst performance in 13 years -- failed to materialise. Growth stood at 7.7 percent in the first three months of this year and slowed further to 7.5 percent in the April-June period, but recent data, including strong exports and industrial output, have pointed to renewed strength in the economy. HSBC said the final September PMI reading will be published next Monday.