The FTSE 100 fell on Monday as weakness in several heavyweight stocks outweighed gains in energy and mining shares. Imperial Brands dropped more than 5% following reports that the tobacco company is preparing to cut thousands of jobs across key markets, including the US and Europe. British American Tobacco also fell more than 4%, while HSBC, Unilever and GSK declined between 0.4% and 1.8%. In contrast, oil majors Shell and BP gained 0.7% and 1.5%, respectively, as crude prices extended their recent advance amid uncertainty over a potential US-Iran agreement to end the conflict and reopen the Strait of Hormuz. Mining stocks also benefited from stronger metals prices, with Fresnillo rising 3.3% and Glencore gaining 2.2%. Elsewhere, Plus500's trading update showed stronger first-half growth driven by higher trading income. Pharos Energy confirmed it would not increase its offer, while Vistry reduced coverage for the housebuilder’s suppliers.