The flash China HSBC Purchasing Managers' Index (PMI) climbed to 51.2 in September from a final 50.1 reading in August, hitting a high not seen since March. A breakdown of the data showed 10 of 11 sub-indices rose in September.

At the midday trading break, the CSI300 index of the leading Shanghai and Shenzhen A-share listings was up 0.9 percent, while the Shanghai Composite Index rose 0.8 percent. If gains hold, this will be their second-straight daily gain after closing last Tuesday at their lowest in six sessions.

The ChiNext Composite Index, China's Nasdaq-like board for high-growth, mainly high-tech start up firms, soared 2.2 percent to a record high. It is now up nearly 70 percent on the year.

Markets in the mainland were trading for the first time since last Wednesday, shut for a two-day Mid-Autumn Festival holiday. They will be closed again from next Tuesday for a week-long National Day holiday.

Hong Kong markets were closed on Friday for the same Mid-Autumn holiday and on Monday morning, by Typhoon Usagi. Trading will resume at 1 p.m local time (0500 GMT).

"We are in between two major holiday periods in the mainland and at month's end, so any gains this week for the large cap A-share market will likely be capped since liquidity supply could be an issue," said Zhang Qi, a Shanghai-based analyst at Haitong Securities.

"Many stocks have also risen a lot in a short time earlier this month, so investors will be looking to lock in some profits as well," Zhang added.

Inner Mongolia Yili Industrial Group jumped 3.5 percent in Shanghai. The official China Business Journal reported on Saturday that Yili is among Chinese milk powder makers set to receive a combined 30 billion yuan ($4.90 billion)to support sector consolidation.

Counters seen benefitting from an approved Shanghai free-trade zone also saw strong gains. Various local media had reported the initiative could be launched at the end of the month or early October.

Shanghai Lujiazui Finance & Trade Zone Development Co Ltd surged by the maximum 10 percent limit, while Shanghai Waigaoqiao Free Trade Zone Development Co Ltd spiked 8 percent.

But Shanghai Pudong Development Bank was weaker, along with most financial counters. Pudong Bank dipped 1.1 percent, underperforming the 0.2 percent loss for the Shanghai financial sub-index.

($1 = 6.1212 Chinese yuan)

(Editing by Jacqueline Wong)

By Clement Tan