Activity in Chinese factories, as measured by the official manufacturing purchasing managers index, declined once again in January.
The manufacturing PMI has been below 50, which indicates contraction, since July.
The January figure came in at 49.4, down from 49.7 in December. *
The non-manufacturing PMI, which measures activity in the services sector, fell 0.9 points from December to 53.4.
Market reaction: The Shanghai Composite fell 1.78%.
- The outgoing president of Taiwan, Ma Ying-jeou, plans to visit the Itu Aba island on Thursday. +
Itu Aba, also known as Taiping, is part of the Spratly Islands and is one of a number of contested islands in the South China Sea.
The trip is dependent on weather conditions being good in the area.
China has been developing a number of airstrips on artificial islands in the South China Sea, significantly escalating tensions in the region.
Last week, a report commissioned by the U.S department of defence warned that if the current state of affairs continues, the South China Sea would effectively be a 'Chinese lake' by 2030.
President Ma met with his Chinese counterpart, President Xi, in November last year - the first meeting between the leaders of China and Taiwan.
Tsai Ing-wen, Taiwan's president elect from the less 'China friendly' Democratic Progressive Party, does not take office until May and is not sending a representative on the trip.
Industrial profits by selected sector in 2015
Profits at large industrial firms in China fell 4.7% year on year in December according to data released on Wednesday, accelerating on November's decline of 1.4%.
For all of 2015, industrial profits were 6,355.4 billion yuan - a 2.3% decrease on 2014.
A breakdown of the data by industry, provided by the National Bureau of Statistics, reveals that the profits of firms in the mining and quarry sector dived 58.2% in 2015.
The manufacturing sectors saw industrial profits rise 2.8% over the course of the year.
Stock exchanges on mainland China closed down on Tuesday as the volatility that has characterised the market this month reemerged.
The Shanghai Composite Index closed down 6.42%.
The CSI 300, which follows 300 stocks on the Shanghai and Shenzhen indexes, closed down 6.02%.
Meanwhile, oil prices fell below $30 a barrel as the rally of recent days fizzled out.