The mining company agreed to sell Las Bambas earlier this year to meet demands from China's antitrust authorities after its takeover of mining group Xstrata. The regulator feared the tie-up handed the newly formed commodities powerhouse too much clout in copper.

Glencore has long reported strong Chinese interest, but there have been questions among industry analysts and observers over whether Chinese authorities will allow competition between Chinese industrial groups, or pick a horse to back.

Chinalco Mining Corp, MMG and Jiangxi Copper are among the Chinese groups interested in the project, sources familiar with the bid have said. One of the sources said Jiangxi, China's largest copper producer, had paired up with Chinalco.

"The interest we have seen in China is very robust, there are groups combining to bid in the process. We see at least three to four (Chinese) groups bidding," Glencore Xstrata Chief Executive Ivan Glasenberg told reporters, adding there were also non-Chinese parties among the suitors.

"There is very strong interest from major (Chinese) groups and they are not in the same consortium. So it seems they are going to compete."

Glencore expects to secure a sale of Las Bambas by the end of the year, though completion could take longer.

(Reporting by Clara Ferreira-Marques; Editing by Andrew Callus)