Mining giant BHP has urged takeover target Anglo American to extend its deadline as talks continue between the two rivals.

The companies have been in talks over a deal worth almost £39 billion since Wednesday May 22 amid efforts to agree on the structure for a potential takeover.

Australia’s BHP faces a deadline of 5pm on Wednesday to make a firm offer or walk away from takeover talks.

The mining firm said it had put forward a number of “socioeconomic measures” in a bid to ease concerns over its bid and called for more time to discuss this with Anglo American.

BHP’s three takeover approaches all had a requirement for its rival to spin off its South African operations, resulting in heavy criticism from the government in Pretoria.

Anglo American also opposed this.

In a statement on Wednesday, BHP said: “BHP believes that the proposed measures it has put forward provide substantial risk protection for Anglo American shareholders and supplement the significant value uplift that Anglo American shareholders will receive from the potential combination.

“BHP believes a further extension of the deadline is required to allow for further engagement on its proposal.

“This announcement does not amount to a firm intention to make an offer and there can be no certainty that an offer will be made.”

A mega-merger between the two companies would create the biggest copper miner in the world, with 10% of global output.

Anglo American’s vast reserves of copper are a key driver of the interest in the business, as the mineral is an important building block for low-carbon technologies such as solar farms and electric cars.

Earlier this month, Anglo American announced plans to break up major parts of the business and heavily slow down its development of a £7 billion North Yorkshire fertiliser mine.