Anglo American’s management does not consider a proposed $39-billion takeover offer from the BHP Group attractive, two sources have told the Reuters, as some investors and analysts dismissed it as opportunistic.

BHP on Thursday had offered Anglo’s shareholders 25.08 pounds ($31.39) per share, or $38.8 billion, a premium of 31 per cent to the market close on Wednesday. It would take over Anglo after a spin-off of two assets.

Speaking on condition of anonymity because the matter was private, one of the sources said the offer did not address the complexities of demerging the Anglo American Platinum and Kumba Iron Ore businesses in South Africa.

BHP has until May 22 to come back with a binding bid.

Anglo, which has market value of $36.7 billion, said that it would be reviewing the offer, without elaborating.

The proposed tie-up would create a group with around one-tenth of the global output of copper, which is in demand for its use in electric vehicles and new technologies, such as automation and artificial intelligence.

BHP has made the offer as Anglo continues a strategic review of its assets started in February in response to a 94 per cent fall in annual profit and a series of writedowns caused by lower commodity demand.