LSE-listed Eurasian Natural Resources (ENRC) must either announce a “firm intention” to make an offer for fellow Kazakh miner Kazakhmys by May 16 or walk away for six months, the UK Takeover Panel has ruled.

The decision was made after the panel held discussions with both parties’ advisers.

Kazakhmys said this week it had applied to the panel for a deadline, after ENRC said on March 12 that one of the opportunities it was considering was a possible merger with Kazakhmys.

Kazakhmys said at the time that it had not received a proposal from ENRC, and confirmed on Tuesday that it had not received anything since.

The firm said on Friday that it "welcomed" the ruling.

Kazakhmys has copper mining, smelting and refining operations in the Zhezkazgan, Balkhash and East regions of Kazakhstan, precious metals mines in Tajikistan and Kyrgyzstan, and copper processing and manufacturing units in Germany.

The company said last month that it had held preliminary talks with the government of Kazakhstan, including on the possibility of the government taking a minority stake in the company in exchange for natural resource assets in the country.