"It is definitely on the table now because the offers that are coming in just aren't high enough," one senior Amplats source, who did not wish to be named, told Reuters.

One Johannesburg-based investment banker also said the company, commonly known as Amplats, had received a few offers for its Union Mine and three others near Rustenburg but had "thrown them into the dustbin" because they were too low.

The Anglo American subsidiary is in the middle of a shake-up that includes selling off underperforming assets in an attempt to recover from a five-month long strike last year.

It said in February it hoped to complete the review and decide whether to sell or list its Union and Rustenburg mines by the end of the first half this year, after evaluating offers for the assets from two shortlists of companies.

(Reporting by Ed Cropley and Tiisetso Motsoeneng; Editing by James Macharia)