China's factory activity expanded for a second consecutive month in June on improved supply and demand, a private survey showed on Monday.

The Caixin China General Manufacturing Purchasing Managers' Index — which gauges operating conditions in the sector — came in at 50.5 in June after 50.9 in May, above the 50-point mark that separates growth from contraction, media group Caixin said on Monday.

Wang Zhe, a senior economist at Caixin Insight Group, said both manufacturing supply and demand improved slightly in June.

While the subindex for manufacturing output remained within the expansion territory for a fifth straight month in June, it expanded at a slower pace last month. And the gauge for new orders also stayed above the 50-point mark for the fourth time during the past five months.

Referring to the 12-month outlook for output, manufacturers polled by Caixin expressed optimism, supported by hopes that economic conditions and sales will improve in the future. However, this business confidence for the coming 12 months slipped to an eight-month low in June, as some manufacturers expressed concerns over relatively sluggish market conditions.