The UK's blue-chip FTSE 100 ticked lower on Wednesday after posting six straight quarterly gains as investors monitored the latest setback in U.S.-Iran talks, with gains in financials and industrials offsetting weakness in energy and mining shares.

The internationally focussed FTSE 100 index CURRENCYCOM:UK100 fell 0.1% by 0923 GMT, while the midcap FTSE 250 FTSE:MCX rose 0.4%.

  • Iran said on Tuesday it would not meet top U.S. envoys, following an outbreak of hostilities between the two nations, clouding the prospects of a peace agreement.

  • Precious FTSE:NMX551030 and industrial (.FTNMX551020) mining shares declined, weighing on the commodity-heavy FTSE 100 with Rio Tinto LSE:RIO and Fresnillo LSE:FRES down 1.1% and 1.7%, respectively.

  • Aerospace and defence shares (.FTNMX502010) extended gains from the prior session when Prime Minister Keir Starmer pledged an extra £15 billion ($20 billion) toward a defence boost. Babcock LSE:BAB, BAE Systems LSE:BA., Rolls-Royce LSE:RR. and Melrose Industries LSE:MRO rose between 1.7% and 4.9%.

  • PMI data showed that Britain's manufacturing activity cooled in June despite a boost from stockpiling ahead of price hikes and supply chain disruption worries.

  • Among individual movers, AB Foods LSE:ABF dropped 2% after the Primark owner said it expects annual profit to be below last year's. The food, beverage & tobacco index (.FTUB4510) slipped 1.5%.

  • Greggs LSE:GRG fell 3.8% and was the top laggard on the mid-cap index after the UK's biggest fast-food chain said its long-time CFO Richard Hutton would step down.

  • JD Sports LSE:JD. shed 2.1% after its retail partner Nike NYSE:NKE reported a decline in fourth-quarter revenue and said it expects a further revenue drop through the first half of 2027.

  • Both the FTSE 100 and FTSE 250 notched quarterly gains. The midcap index posted its biggest quarterly rise in five quarters, while the blue-chip index ended higher in 11 of the last 12 months.