The European Union is set to propose a voluntary 15% cut in natural gas use by member states starting next month on concern Russia may halt supplies of the fuel. The goal would be embedded in a regulation accompanying a demand-reduction plan the European Commission is scheduled to unveil Wednesday to cope with a potential full cutoff by Moscow. The measure also would include a mandatory trigger if the situation worsens and voluntary curbs are insufficient, according to three EU diplomats with knowledge of the matter. Under its “Save gas for a safe winter” plan, the commission plans to recommend steps that include reducing heating and cooling, as well as market-based measures. As much as 1.5% of the region’s gross domestic product is at risk in the event of a harsh […]