Controlling shareholder Aluminum Corporation of China (Chinalco) and its concert parties plan to increase their stake in Aluminum Corporation of China (HKG:2600, SHA:601600) or Chalco over the next 12 months, according to a Monday Hong Kong bourse filing.

Chinalco will purchase about 1 billion yuan to 2 billion yuan worth of shares across the Hong Kong and Shanghai bourses.

The stake increase will not exceed 2% of Chalco's total share capital, and the purchases will be funded through internal or self-raised funds.

Chinalco and its concert parties currently hold about 33.55% of Chalco's total share capital. The planned purchases will not change the company's controlling shareholder or de facto controller.

Chalco's shares jumped 4% in Shanghai trading, while its Hong Kong-listed shares rose nearly 2% Monday morning.