Electronic trading on the London Metal Exchange resumed after an outage that kept the exchange's screen-based venue offline for close to three hours, according to a report by Mining.com.

The halt took LMEselect — the exchange's electronic trading platform for base metals including copper, aluminium and zinc — out of action for nearly 180 minutes. Inter-office telephone trading, the LME's older channel, remained the fallback execution route while screens were dark, as is standard practice when the electronic venue goes down.

For trading desks, the practical consequences were immediate. Any algorithmic or automated strategies pointed at LMEselect stopped receiving fills or market data from the platform for the duration of the outage. Order flow that could not wait for the venue to return had to move to voice execution, with the operational risk that implies: manual ticketing, weaker timestamp granularity and slower confirmation cycles relative to screen trading. Risk systems that mark positions off exchange-published prices also faced a gap in primary data feeds while the platform was down.

The outage duration — just under three hours — matters for post-trade workflow. Depending on when the halt began relative to the LME's trading calendar, it cut into open-outcry-adjacent sessions and the intraday pricing windows that members use for margining and client reporting. Compliance teams at member firms will want the exchange's incident timeline: when the fault was detected, when members were notified, and what the formal status of open orders was during the suspension.

The LME has form here that desks will factor into their operational planning. The exchange was at the center of the March 2022 nickel crisis, when it cancelled trades and suspended the nickel market — a sequence that triggered lawsuits and a £9.2 million fine from UK regulator the FCA in 2024 for failings in its oversight of that episode. That history means any fresh platform disruption draws closer scrutiny than it might at another venue.

Mining.com's report confirms the resumption of electronic trading but does not state the technical cause of the outage, whether any orders were affected at the point of failure, or whether the exchange plans a formal incident review. Those gaps define the follow-up questions for members: the LME's post-incident notice, if one is issued, will determine whether desks need to adjust connectivity, failover or voice-trading procedures ahead of the next session.