A Chinalco spokesman declined to comment on the issue, while SPI was not immediately available for comment.

China vowed in late 2013 to restructure its huge and debt-ridden State sector.

Total profits at central government-owned State firms fell 4.5 percent in the first seven months of the year to 1.005 trillion yuan ($157 billion) from the same period a year earlier.

The move is expected to cut the total number of central government-owned SOEs from 111 to around 40, according to media reports, and is aimed at eliminating duplication, waste and "cut-throat competition" between firms with nearly identical business structures.

However, the release of a reform masterplan has been repeatedly delayed, with SASAC researcher Li Jin telling local media this week it had to balance and coordinate "conflicts" between government departments and enterprises.