The ProInversion investment promotion agency had planned to auction the project on November 15 but has pushed this back to December 20. 

In a translated statement, the agency said the extended period will allow more companies to participate, and communities in the area of influence to be involved in workshops.

ProInversion anticipates an investment in the order of $2 billion for the porphyry project, which contains copper, gold, silver and molybdenum, and has an estimated 1.16 billion tonne resource at 0.629% copper using a 0.4% cut-off.

Anglo American (LN:AAL) previously held the project but returned it to the government in late 2014 under plans to prioritise capital and cut its global exploration expenditure.

Companies must now register by November 2 and ProInversion said the project would be awarded this year.