ENRC (LON:ENRC) is reportedly the subject of a takeover bid from a consortium made up of the Kazakh miner’s three founders and the government.
Together the members, including reclusive Russian billionaire Alexander Machkevitch, already own more than 55% of the company.
Machkevitch, who has a 14.6% stake, said he is weighing up his options, as well as a full takeover of the company with fellow founders Alijan Ibragimov, Patokh Chodiev and the Kazakh government.
Shares leapt by more than a quarter to 292p each, despite Machkevitch insisting that it is too early to say whether they will table a bid.
It is as yet unknown what Kazakhmys, ENRC’s largest shareholder at 26%, plans to do with its stake. Its shares also rose 22% to 379p.
ENRC’s shares have been under intense pressure over the past year with the share price down by half amid fears over growth in China, the world’s largest importer of metals.
The miner has until January 2014 to boost its free float, which is currently less than 20%, or quit the FTSE 100.