Talks between BHP and Anglo American have failed so far to bridge their differences, and the Australian miner is reportedly set to ask for an extended deadline to reach an agreement.

BHP has until 5pm in London on Wednesday (2am on Thursday AEST) to commit to an offer, after Anglo agreed to extend a previous cut-off to allow for discussions. The two sides were getting closer on a value for a potential deal, Bloomberg reported last week, and BHP chief executive Mike Henry has jetted into London for last-ditch meetings with investors before the deadline.