Aluminum Corp. of China, or Chinalco, said Friday it signed a $21 billion syndicated loan agreement with four Chinese banks to fund its $19.5 billion purchase of Rio Tinto PLC (RTP) and other expenditures related to the investment.

China Development Bank Corp. led the syndicate of banks, which also included Bank of China Ltd. (3988.HK), Agricultural Bank of China, and Export-Import Bank of China, Chinalco said in a statement.

"The credit facility will help the company smoothly proceed with its investment (in Rio Tinto)," Chinalco President Xiong Weiping said in the statement.

Aluminum Corp. of China Ltd. (ACH), or Chalco, is the listed unit of Chinalco.

-Juan Chen contributed to this story; Dow Jones Newswires; 8610 6588 5848; juan.chen@dowjones.com